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EASY  LESSONS 


IN 


Vegetable  Biology; 


OR, 


Outlines  of  Plant  Life. 


REV.  J.  H.  WYTHE,  M.D., 

Author  of  "The  Science  of  Life,"   "The  Microscopist,"   "Agreement 
of  Science  and  Revelation,"  etc. 


CINCINNATI: 
WALDEN     &     STOWE. 

1883. 


Cfttt 

Copyright  1883,  by 
PHILLIPS    &    HUNT, 

New  York. 


PREFACE. 


This  work  has  been  prepared  for  the  students  of  the 
Chautauqua  Literary  and  Scientific  Circle.  It  is  also 
adapted  to  use  in  schools. 

It  begins  with  the  simplest  and  most  elementary 
facts  of  Biology,  and  progresses  gradually  to  things 
more  intricate.  It  uses  no  unnecessary- technicalities, 
is  condensed  into  the  smallest  possible  compass,  and 
but  few  words  are  spent  upon  theories.  The  Chris- 
tian philosophy  of  life,  which  the  author  believes  to 
be  the  only  true  philosophy,  is  clearly  stated ;  but  he 
aims  to  present  only  facts,  and  the  plain  inferences 
from  facts,  to  the  attention  of  the  inquirer. 


^^  Of  XBDB^^S 

[BHIVBRSITY] 


CONTENTS. 


CHAPTER  PAGK 

I.  What  Biology  Teaches 7 

II.  Living  Matter 12 

III.  Differences  between  Living  and  Non-living  Matter  17 

IV.  Different  Kinds  of  Living  Matter 23 

V.  Individual  Vegetable  Cells 27 

VI.  The  Vegetable  Cell  as  a  Member  of  a  Group 33 

VII.  Protophytes,  or  the  Simplest  Forms  of  Plants 40 

VIII.  Thallogens,  or  Division  of  Labor  in  Plants 46 

IX.  Acrogens,  or  Plants  which  Grow  at  the  Summit..  . .;  50 

X.  Endogens,  or  Inside-growers 58 

XL  Exogens,  or  Outside-growers u 


XII.  The  Vegetable  Clothing  of  the 
Glossary  and  Index 


World 80 

85 


[UITIVBBSITY] 


^£2 

EASY    LESSONS 

IN 

VEGETABLE   BIOLOGY. 


CHAPTER  I. 

WHAT    BIOLOGY    TEACHES. 

1.  The  word  Biology  is  made  up  of  two  Greek 
words — bios,  life,  and  logos,  a  discourse.  It  means  the 
study  of  living  things. 

A  few  years  ago  all  the  living  and  non-living  ob- 
jects in  the  earth — minerals,  plants,  and  animals — were 
embraced  in  one  department  of  knowledge,  called 
Natural  History,  but  it  is  now  usual  to  study  living 
and  non-living  objects  in  different  departments.  A 
knowledge  of  Biology  involves  much  more  than  the 
ability  to  distinguish  the  different  kinds  of  living 
beings  so  as  to  be  able  to  label  dead  specimens  in  a 
cabinet.  This  science  uses  the  terms  of  Botany  and 
Zoology  only  as  the  builder  uses  a  scaffolding  for  the 
erection  of  an  edifice,  or  as  a  postmaster  the  boxes  of 
his  office  for  a  more  convenient  classification. 

2.  Biology  includes  in  its  survey  both  animals  and 
vegetables,  and  considers  their  forms  and  peculiarities, 


8  Easy  Lessons  in  Vegetable  Biology. 

the  parts  of  which,  they  are  composed,  their  relations 
to  each  other,  and  the  uses  which  they  serve.  It  takes 
in  the  entire  life-history  of  every  living  thing,  with 
the  changes  which  occur  in  health  and  disease.  If 
fully  recorded,  the  world  would  hardly  hold  the  books 
which  might  be  written  about  these  things,  since  there 
are  many  thousands  of  species,  or  different  kinds, 
both  animal  and  vegetable;  and  the  influences  to 
which  they  are  subject  are  quite  innumerable.  Yet 
many  observations  and  comparisons  have  shown  that 
one  kind  agrees  with  another  in  certain  particulars, 
so  that  the  general  principles  which  underlie  their 
forms,  changes,  structure,  and  uses  may  be  under- 
stood. The  consideration  of  these  general  principles 
and  correspondences  makes  up  the  chief  part  of  the 
study  of  Biology. 

3.  Biology  studies  only  living  beings.  The  general 
forces  of  nature  and  the  changes  in  non-living  matter 
are  the  subjects  of  Physics  and  Chemistry.  Biology 
only  refers  to  these  changes  as  they  affect  living 
things,  or  are  modified  by  the  presence  of  life. 

4.  Those  astronomers  who  still  hold  to  the  Nebular 
hypothesis — the  theory  that  the  sun  and  planets  de- 
veloped themselves  out  of  a  sort  of  fiery  vapor  or 
nebulous  matter — teach  us  that  only  a  few  of  the 
planets  of  our  solar  system  are  capable  of  sustaining 
life,  and  chemical  analysis  shows  that  only  four  out 
of  nearly  seventy  elementary  or  simple  substances,  of 


What  Biology  Teaches.  9 

which  the  world  is  composed,  are  found  essentially 
connected  with  living  beings.  Geology  also  shows  us 
that  there  were  vast  periods  in  the  past  history  of  the 
earth  when  no  life  existed.  These  periods  are  hence 
called  azoic,  or  without  life.  At  the  present  time, 
the  ice-fields  of  the  poles,  and  the  great  deserts,  are  to 
a  large  extent  lifeless.  It  is  plain,  therefore,  that  life 
is  not  an  essential  part  of  creation.  Suns  and  planets 
would  shine ;  gravity,  light,  heat,  and  electricity 
would  operate ;  and  chemical  changes  take  place,  if 
there  were  no  living  beings.  From  this  consideration 
we  see  clearly  that  Biology  embraces  something  more 
than  the  study  of  the  laws  and  phenomena  of  non- 
living matter.  It  is  the  science  of  life.  It  concerns 
itself  with  every  thing  pertaining  to  life. 

5.  The  question,  What  is  life  ?  has  given  rise  to  vari- 
ous speculations  in  every  age  of  history  to  the  present 
day.  Some  of  the  Greek  philosophers  taught  that 
it  was  the  result  of  the  harmony  or  agreement  of  the 
different  parts  of  the  body ;  and  this  view  is  repeated 
in  modern  times  by  those  who  claim  that  life  is  the 
result  of  organization.  It  requires  but  little  thought 
to  see  that  this  is  no  explanation  at  all.  Since  all 
organization  depends  on  living  matter,  as  we  shall 
more  fully  perceive  hereafter,  one  might  as  wisely 
say  that  an  architect  or  carpenter  was  the  result  of  a 
house,  as  to  say  that  life  results  from  organization. 

Some  have  claimed  that  life  is  a  sort  of  refined 


10        Easy  Lessons  in  Vegetable  Biology. 

matter ;  a  gas,  or  ethereal  vapor.  Heat,  oxygen,  and 
galvanism  have  all  had  their  advocates,  and  at  the 
present  day,  when  teachers  of  physical  science  show 
that  one  kind  of  force  (as  motion,  light,  heat,  or  elec- 
tricity) can  be  converted,  or  changed,  into  another, 
some  are  found  to  say  that  physical  force  can  be 
changed  into  life,  or  vital  force.  But  this  theory  is 
insufficient  to  explain  what  life  is,  since  it  does  not 
show  what  is  meant  by  "  physical  force,"  nor  what 
changes  its  form.  Life  must  either  be  the  power  of 
matter  or  spirit,  for  we  can  only  conceive  of  these  two 
forms  of  existence.  This  theory  is  also  insufficient, 
since  it  does  not  account  for  the  living  germ  through 
which  (according  to  the  theory)  heat  or  other  form  of 
force  passes  in  order  to  be  converted  into  vitality. 

6.  Writers  who  have  endeavored  to  define  life  in 
accordance  with  the  teaching  of  materialism — which 
makes  matter  explain  every  thing — have  involved 
themselves  in  unsatisfactory  and  often  absurd  con- 
clusions. The  teaching  of  the  Bible  and  of  all  the  re- 
ligions of  mankind,  the  belief  of  the  most  eminent 
philosophers,  the  doctrine  held  by  the  early  Christian 
fathers,  and  maintained  by  the  majority  of  scientific 
and  unscientific  men,  is  that  the  difference  between  a 
living  body  and  the  same  body  after  death  arises  from 
the  union  of  matter  and  spirit.  In  other  words,  a 
living  thing  is  a  spiritual  essence  which  clothes  itself 
with  material  particles  after  a  form  and  according  to 


What  Biology  Teaches.  11 

an  order  (or  law)  of  its  own  kind.  Dr.  Noah  Porter, 
President  of  Yale  College,  in  his  work  on  the  "  Hu- 
man Intellect,"  devotes  an  entire  chapter  to  prove 
that  life  and  soul  are  synonymous  words,  and  apply 
to  all  living  things.  The  writer  of  the  present  work, 
in  the  volume  entitled  "  The  Science  of  Life,"  regards 
life,  not  as  identical  with  soul,  but  as  the  sum  of  the 
activities  resulting  from  the  union  of  mind  and  mat- 
ter. Those  who  desire  to  study  the  subject  more 
thoroughly  are  referred  to  those  works. 


12        Easy  Lessons  in  Vegetable  Biology. 


CHAPTER  II. 

LIVING      MATTER. 

1.  A  careful  study  of  any  living  thing,  either 
vegetable  or  animal,  will  show  that  it  is  not  all  alive. 
Some  parts  are  dead,  although  they  may  retain  the 
form  impressed  on  them  by  vitality,  as  in  the  case  of 
a  dry  branch  of  a  tree,  and  may  serve  various  pur- 
poses in  relation  to  the  rest  of  the  body,  like  resin  in 
some  plants  and  milk  in  animals.  When  we  clip  the 
hair,  or  pare  the  nails,  we  cut  merely  the  dead,  in- 
sensitive part ;  but  at  the  root  of  the  hair  or  nail  we 
find  the  "  quick  " — the  living  part.  By  the  use  of 
the  microscope  it  has  been  found  that  every  part  of 
every  living  body,  or  organism,  has  scattered  through 
it  little  particles  of  living  matter.  In  the  skin,  flesh, 
bones,  and  nerves  of  animals,  and  in  all  the  different 
parts  of  vegetables,  these  small  particles  of  living 
matter  may  be  seen  by  a  good  instrument.  It  is  the 
presence  of  this  living  matter  which  entitles  any  thing 
to  be  called  a  living  being.  Without  this  a  man,  a 
horse,  a  tree,  or  a  flower,  would  be  as  dead  as  a  piece 
of  iron  or  chalk. 

2.  This  living  matter,  seen  through  the  microscope, 
looks  like  a  bit  of  jelly  or  albumen.     It  is  generally 


Living  Matter.  13 

transparent,  and  is  neither  quite  solid  nor  fluid. 
When  it  was  first  discovered  it  was  thought  to  be  in- 
closed in  a  sort  of  membrane  like  a  bladder,  and  it 
was  called  a  cell.  It  is  now  known  that  it  has  not  al- 
ways an  outside  membrane.  It  is  often  called  proto- 
plasm, or  first  formation.  It  is  also  called  by  the 
better  term  hioplasm,  or  living  formation.  Some  re- 
cent discoveries  with  the  microscope  render  it  likely 
that  the  real  living  matter  in  each  cell,  or  piece  of 
bioplasm,  is  arranged  like  a  net-work,  and  communi- 
cates with  neighboring  cells  so  as  to  make  a  continu- 
ous living  structure  throughout  the  body,  either  of 
plant  or  animal. 

Those  who  have  access  to  a  good  microscope  may 
find  an  example  of  this  living  matter,  or  bioplasm,  in 
the  white  blood-cell.  Prick  your  finger,  and  put  a 
small  drop  of  blood,  about  the  size  of  a  full  "  stop  " 
— printer's  type — upon  the  thin  glass  cover  of  a  mi- 
croscopic slide,  then  quickly  put  the  cover  in  its 
place,  so  that  the  drop  may  spread  by  capillary  attrac- 
tion, and  observe  the  globules  in  the  field  of  view  of 
the  instrument.  In  about  every  three  hundred  of  the 
ordinary  red  blood-disks  you  will  see  one  of  the  white 
disks.  If  you  keep  it  warm  by  a  heated  stage,  or  if 
you  examine  the  blood  of  a  cold-blooded  animal,  as  a 
frog,  instead  of  your  own,  you  will  be  able  to  see  its 
peculiar  motions  and  other  phenomena. 

3.  From  such  simple,  jelly-like  particles  all  animals 


. 


14        Easy  Lessons  in  Vegetable  Biology. 

and  vegetables  originate,  and  by  such  particles  are  all 
organic  structures  built  up.  Bone,  muscle,  nerve,  and 
skin,  in  animals,  and  fiber,  wood,  and  vessels,  in  vege- 
tables, are  all  constructed  from  such  elements.  It  is 
the  province  of  biology  to  find  out  how  this  is  done. 

4.  The  particles  of  bioplasm,  or  living  matter,  al- 
ways look  alike,  no  matter  where  they  belong.  There 
is  no  difference  under  the  microscope  between  the  bi- 
oplasm of  a  blade  of  grass  or  a  whale,  of  an  oak,  a 
rose,  a  dog,  or  a  man.  The  bioplasm  of  skin  cannot 
be  distinguished  from  that  of  flesh,  or  of  the  blood, 
yet  there  is  a  wonderful  difference  in  the  power  and 
products  of  these  different  kinds,  although  the  differ- 
ence is  not  visible  even  with  a  microscope. 

Chemical  examination  also  shows  that  all  living 
matter  is  composed  of  the  same  elementary  materials. 
Oxygen,  hydrogen,  carbon,  and  nitrogen  enter  into 
the  construction  of  every  piece  of  bioplasm.  Some- 
times lime,  or  iron,  or  sulphur  are  also  found,  but 
these  are  accidental,  and  not  essential  or  necessary. 

5.  The  jelly-like  living  matter  which  has  been  de- 
scribed, like  any  other  jelly,  is  permeated  or  satu- 
rated with  fluid,  which  may  be  considered  apart  from 
the  rest  of  the  structure.  All  organic  substances  con- 
tain considerable  water.  A  human  body  weighing  a 
hundred  and  fifty  pounds  can  be  dried  in  an  oven 
until  it  weighs  only  seven  and  a  half  pounds.  The 
water  in  a  piece  of  bioplasm  may  also  contain  other 


Living  Matter.  15 

substances  in  solution  which  may  serve  the  living  mat- 
ter as  food.  In  the  spaces  between  the  minutest  parti- 
cles or  net-work  of  bioplasm  we  may  also  find  mate- 
rial which  has  been  formed  by  it.  So  that  in  every 
bioplast,  or  living  particle,  we  recognize  matter  in 
three  different  states :  (1)  Matter  not  yet  alive,  but 
about  to  become  so,  called  Pabulum,  or  nutriment. 

(2)  Living  matter  in  the  strictest  sense,  or  Bioplasm. 

(3)  Formed  material,  or  matter  which  was  alive,  but 
is  so  no  longer. 

Owing  to  the  constant  action  of  the  air  and  other 
influences,  the  formed  material  is  constantly  decay- 
ing, or  becoming  effete,  and  thus  returns  to  the  inor- 
ganic world  from  which  it  originated,  so  that  we  may 
say  of  the  body  of  any  living  thing — though  not  of 
the  life — u  Dust  thou  art,  and  unto  dust  shalt  thou 
return." 

6.  Physical  forces,  like  gravity,  heat,  light,  and 
electricity,  and  chemical  agencies,  affect  all  living 
matter  as  well  as  the  non-living,  but  not  always  in 
the  same  manner.  Some  forces,  as  gravity,  for  ex- 
ample, act  in  the  same  way  on  the  living  and  the  non- 
living. The  passage  of  liquid  out  of  or  into  a  porous 
or  membranous  vessel  is  similar  in  a  living  or  non- 
living thing.  In  other  instances  the  presence  of  life 
greatly  modifies  the  influence  of  inorganic  force. 
Thus,  water  generally  freezes  at  32  deg.  F.,  and  boils 
at  212  deg.;  but  bioplasm,  or  living  matter,  resists  the 


16        Easy  Lessons  in  Vegetable  Biology. 

extremes  of  lieat  and  cold  as  long  as  the  life  remains. 
There  are  differences  in  this  respect  in  different  or- 
ganisms. The  motions  of  some  simple  forms  of  ani- 
mals are  arrested  by  ice-water,  and  recommence  on 
increasing  the  temperature,  but  the  development  of 
trout's  eggs  proceeds  well  in  ice-water,  while  in  a 
warm  room  they  soon  die.  Many  kinds  adapt  them- 
selves to  a  considerable  change  of  temperature  if  it  be 
gradual.  Men  will  endure  the  cold  of  an  Arctic  win- 
ter, and,  on  the  other  hand,  the  workers  in  plaster 
will  bear  for  a  considerable  time  the  heat  of  an  oven 
raised  to  500  deg.  F.  The  influence  of  light,  heat,  and 
electricity  upon  bioplasm  varies  according  to  the  spe- 
cies, some  requiring  a  greater  amount  than  others  for 
natural  growth.  As  to  chemical  changes,  the  life 
power  has  greater  modifying  power  than  any  thing 
else  in  nature.  A  vast  variety  of  products  in  both 
animals  and  vegetables  are  due  to  the  controlling 
influence  of  life.  In  a  few  instances  the  skill  of  a 
chemist  has  imitated  the  product  in  his  laboratory, 
but  the  majority  can  only  be  found  as  the  result  of 
life.  Among  them  may  be  named  albumen,  starch, 
sugar,  and  gum.  Many  others  will  occur  to  us  as 
we  proceed  in  our  studies.* 

*  See  "  Science  of  Life,"  Chap.  IY. 


Living  and  Non-living  Matter.  17 


CHAPTER  III. 

DIFFERENCES  BETWEEN  LIVING  AND  NOtf-HVING 
MATTER. 

1.  The  jelly-like  bioplasm  described  as  existing  in 
all  kinds  of  vegetables  and  animals,  and  forming  all 
sorts  of  organic  materials,  is  so  different  in  power 
from  non-living  matter  as  to  compel  us  to  believe 
that  it  contains  something  more  than  mere  matter. 
Each  kind,  or  species,  of  living  being  can  do  some- 
thing which  is  peculiar  to  itself,  yet  there  are  certain 
particulars  in  which  all  kinds  agree,  or  things  which 
all  sorts  of  bioplasm  can  do,  but  which  no  matter  can 
do  which  is  not  alive. 

2.  All  bioplasm  has  spontaneous  motion.  Most 
vegetables  are  fixed  to  one  spot,  but  the  living  matter 
in  their  tissues  is  just  as  much  in  motion  as  the  bio- 
plasm of  the  most  active  animals,  so  that  the  same 
things  may  be  said  of  either  animal  or  vegetable  bio- 
plasm. Non-living  matter  is  passive.  It  has  inertia* 
It  can  neither  originate,  suspend,  nor  destroy  motion. 
It  can  only  transmit  motion,  or  be  moved.  But  bio- 
plasm, or  living  matter,  has  primary  energy,  and  can 
overcome  inertia.     Its  motions  are   spontaneous,  or 

*  A  property  of  matter  which  causes  it  to  remain  in  a  state  of  rest 
or  of  motion. 
2 


18        Easy  Lessons  in  Vegetable  Biology. 

spring  from  its  own  internal  energy.     So  far  from 
being  caused  by  external  influence,  its  movements  are 
often  in  direct  opposition  to  gravity,  or  any  other 
force  which  we  may  imagine  to  act  upon  it. 
The  motions  of  bioplasm  are  of  three  kinds : 

(1)  Inherent  motions  of  the  individual  particles 
among  themselves.  Each  particle  is  as  much  alive  as 
the  whole  mass,  and  the  movements  of  each  are  spon- 
taneous. If  a  thread  or  filament  of  bioplasm  be  ex- 
amined in  a  powerful  microscope,  the  motions  of  the 
particles  may  be  observed  by  the  granules  of  formed 
material  (Sec.  5,  Chap.  II)  which  may  be  scattered 
through  the  mass.  "  As  the  passengers  in  a  crowded 
street  may  go  the  full  length  of  the  street,  or  turn 
back,  or  stop  and  double,  as  many  times  as  they  wish, 
so  do  the  particles  move  in  the  mass  of  bioplasm. 
Up,  down,  across,  backward,  and  in  all  directions. — 
even  through  each  other — do  these  molecules  move, 
each  impelled  by  its  own  inherent  energy."  * 

Observe  another  motion  of  bioplasm : 

(2)  Constant  change  of  shape.  A  piece  of  bio- 
plasm never  remains  at  rest.  If  unconfined,  its  exter- 
nal appearance  or  shape  is  continually  changing. 
This  has  been  called  amoeboid  motion,  from  the  name 
given  to  one  of  the  simplest  forms  of  living  beings 
known,  the  Amoeba. 

Fig.  1.  This  appears  to  be  simply  a  piece  of  bio- 

*  ••  Science  of  Life." 


Living  and  Non-living  Matter.  10 

plasm,  or  living  jelly,  yet  it  is  a  complete  organism. 
Its  organs,  however,  are  all  extemporaneous.  It 
never  retains  the  same  outline  or  form,  and  it  can 
project  any  part  of  its  substance  in  the  shape  of  an 


Fig.  l. 

arm  or  branch,  and  if  it  touches  any  thing  which 
may  serve  it  as  food,  the  rest  of  the  body  will  flow 
around  it  and  digest  it.  Indigestible  parts  it  discards 
by  flowing  away  from  them.  It  literally  swallows 
without  a  mouth,  digests  without  a  stomach,  and 
moves  without  muscles,  while  a  small  fragment  of  its 
substance  is  capable  of  repeating  the  same  things  as  an 
independent  organism.  Such  living  Amoebae  are  found 
in  stagnant  pools  of  water  and  many  other  places. 
Since  every  piece  of  bioplasm  has  similar  changes  of 
shape,  it  is  agreed  to  call  such  changes  amoeboid. 

(3)  Wandering  movements.  As  unconfined  bio- 
plasm can  flow  along  an  arm  or  branch  of  its  own 
body  around  its  food,  it  can  in  the  same  manner 
change  its  position  from  place  to  place.     In  this  way 


20         Easy  Lessons  in  Vegetable  Biology. 

the  white  blood-cells,  described  in  Sec.  2,  Chap.  II, 
wander  out  of  the  blood-vessels  in  order  to  construct 
the  various  parts  of  the  body  as  they  may  be  needed. 
(Fig.  2.) 

3.  Another  peculiarity  of  living  matter  is  the 
power  of  nutrition  and  growth.  The  non-living  in- 
creases in  size  by  external  additions,  but  bioplasm 
selects  appropriate  material  from  its  food,  (or  pabu- 
lum,) changes  the  chemical  relations  of  this  material, 


Fig.  2. 

and  appropriates  it  to  its  own  structure  in  such  a  way 
that  it  grows  from  within.  It  is  altogether  different 
from  the  enlargement  of  a  crystal,  or  of  the  increase 
of  any  thing  without  life. 

4.  Bioplasm  can  generate  or  reproduce  its  own 
kind  of  living  matter.  No  living  being  exists  which 
did  not  originate  from  living  matter  of  a  similar 
kind.  Some  persons  have  thought  that  they  have 
seen  the  beginning  of  life  in  some  forms  of  simple 
beings,  originating  by  what  has  been  called  sponta- 


Living  and  Non-living  Matter.  21 

neons  generation,  bnt  a  careful  examination  proves 
them  to  have  been  mistaken.  Microscopic  living 
beings  appear  after  a  time  in  water  where  vegetable 
or  animal  matter  has  been  left  to  decay,  but  we  now 
know  that  their  eggs  or  seeds,  in  the  shape  of  very 
minute  particles  of  bioplasm,  are  to  be  found  in  great 
numbers  floating  about  in  the  air  and  in  every  collec- 
tion of  water,  and  that  these  seeds  or  eggs  retain 
their  life-powers  after  having  been  subjected  to  boil- 
ing heat.  Of  course  there  was  a  first  animal  or  vege- 
table of  each  kind,  and  some  learned  men  think  it 
wTas  the  offspring  of  another  kind,  not  quite  like  it, 
by  some  sort  of  change  of  form  or  of  activity,  so 
that  the  more  complicate  forms  sprang  from  more 
simple  ones.  This  doctrine  of  "  evolution,"  as  it  is 
called,  has  never  been  proved  by  facts,  although  the 
varieties  existing  in  the  same  species,  as  the  different 
kinds  of  dogs  or  pigeons,  give  it  a  sort  of  probability 
to  some  persons.  All  kinds  of  living  beings,  how- 
ever, spring  from  similar  parents,  and  none  have  ever 
been  known  to  change  into  other  forms.  The  forms 
pictured  upon  the  monuments  of  early  Egyptian  his- 
tory are  similar  to  those  of  the  present  day.  New 
varieties,  not  new  kinds,  may  be  produced  by  culture, 
as  in  the  case  of  roses  and  other  flowers,  but  such  will 
return  to  their  original  form  if  allowed  to  grow  wild. 
5.  The  power  of  a  living  thing  to  preserve  its  own 
identity  amid  all  the  material  changes  which  take 


22         Easy  Lessons  in  Vegetable  Biology. 

place,  is  entirely  different  from  the  power  of  mere 
matter.  In  Chap.  II  we  learned  that  oxygen,  hydro- 
gen, carbon,  and  nitrogen  are  found  in  every  par- 
ticle of  bioplasm,  and  that  sometimes  a  few  other 
chemical  elements  occur  accidentally.  Now  these 
things  do  not  remain  quiet  in  living  matter.  Atom 
by  atom  they  quickly  pass  through  it.  They  are 
seized  by  the  bioplasm  as  food,  transformed  into  its 
own  structure,  and  then  are  changed  into  formed 
material,  as  starch,  wood,  gum,  oil,  etc.,  in  vegetables, 
and  blood,  muscle,  bone,  and  nerve  in  animals.  The 
formed  material  decays  atom  by  atom  and  is  cast  off, 
to  mingle  again  with  the  inorganic  elements  of  the 
world.  During  all  these  changes  the  living  being 
preserves  its  identity  and  power.  Thus  it  is  possible 
that  an  atom  of  oxygen  or  hydrogen  may  be  cast  off 
from  some  of  the  bioplasts  of  our  own  bodies,  be 
wafted  by  the  air  to  the  sides  of  the  Andes,  be  ap- 
propriated to  the  use  of  the  bioplasm  in  one  of  the 
cinchona-trees,  and  return  to  us  in  the  form  of  qui- 
nine, perhaps  to  cure  us  of  ague.  The  possibilities  of 
science  exceed  the  most  romantic  imagination.  The 
preservation  of  its  identity  shows  that  the  life  of  bio- 
plasm differs  from  the  atoms  which  come  to  and  go 
from  it.  It  does  not  depend  upon  the  new  ones,  for 
it  existed  without  them,  nor  upon  the  old  ones,  for 
it  remains  without  them.  Life  is  not  matter,  but 
matter's  master. 


Different  Kinds  of  Living  Hattek.        23 

*&*  Of  THU^^S 

pIJVMSITy] 

OHAPTEE  IV.^ 

DIFFERENT  kinds  of  living  matter. 

1.  We  have  learned  in  former  lessons  that  the  ele- 
mentary particles  of  living  matter  look  alike  and  have 
the  same  essential  composition,  although  they  may 
belong  to  different  kinds  of  living  beings,  and  may 
serve  very  different  purposes. 

2.  Different  bioplasts  produce  different  forms  of 
living  things  by  the  special  instincts  (or  tendencies) 
belonging  to  each  kind.  These  different  forms  are 
arranged,  or  classified,  in  Botany  and  Zoology,  not 
only  for  convenience  of  study,  but  as  far  as  possible 
in  accordance  with  the  plan  of  Creative  Wisdom, 
which  has  assigned  to  each  its  place  in  the  order  of 
nature. 

3.  The  thousands  of  different  kinds  of  vegetables 
and  animals  could  not  be  remembered ;  but  by  group- 
ing certain  kinds  together,  which  are  in  some  respects 
similar,  and  by  combining  these  groups  with  others, 
naturalists  are  able  to  form  something  like  an  orderly 
system.  Such  a  system  will  be  a  natural  system  if  the 
grouping  be  according  to  existing  resemblances  or  true 
affinities,  otherwise  it  will  be  an  artificial  system.  An 
illustration  of  a  natural  system  of  classification  may  be 


24        Easy  Lessons  in  Vegetable  Biology. 

found  in  a  house,  considered  as  a  building.  Let  us 
suppose  that  all  kinds  of  houses  may  be  referred  to  one 
or  other  of  three  types,  or  general  plans — the  Oriental 
type  with  a  dome  roof,  the  Grecian  type  with  a  flat 
roof,  or  the  Gothic  type  with  a  pointed  roof.  We 
select  a  house  of  the  Grecian  type.  But  there  are 
several  classes  of  the  same  type,  as  made  of  wood, 
iron,  or  stone.  Our  supposed  house  is  a  wooden  one. 
But  there  are  several  orders  in  each  class.  Thus 
we  may  have  Pine,  Oak,  Mahogany,  etc.  The  house 
we  are  considering  is  built  of  oak.  In  each  order 
there  are  other  groups,  or  genera.  The  doors  may  be 
at  the  front  or  at  the  side.  Of  the  kind,  or  genus, 
having  the  door  at  the  front,  there  are  more  specific 
kinds,  according  to  the  resident.  In  our  supposed 
case,  the  specific  house  is  John  Smith's.  Thus,  if  we 
have  rightly  classified  we  have  learned  that  John 
Smith's  kind,  or  species,  of  house,  is  of  the  genus,  or 
group,  which  has  front  doors  belonging  to  the  larger 
group,  or  order,  of  houses  built  of  oak.  This  again 
is  grouped  in  the  class  of  wooden  houses  under  the 
Grecian  type. 

In  a  similar  manner  naturalists  try  to  group  to- 
gether living  things  according  to  their  real  relation- 
ships. All  systems,  however,  are  imperfect,  on  ac- 
count of  our  imperfect  knowledge,  and  we  need  not 
be  surprised  to  find  one  naturalist  referring  a  form 
to  a  group  very  different  from  that  to  which  it  is 


Different  Kinds  of  Living  Matter.         25 

referred  in  the  scheme  of  another,  since  men  differ 
greatly,  not  only  in  knowledge,  but  in  opinion. 

Types  represent  general  plans  of  structure.  Classes 
are  formed  by  the  special  modification  of  a  type. 
Orders  are  groups  of  the  same  class  related  by  a  com- 
mon structure.  A  Family  or  Genus  is  a  still  smaller 
group  having  generally  the  same  essential  structure. 
A  Species  is  the  smallest  group  whose  structure  is 
constant.  Species  are  so  much  alike  that  they  may 
have  descended  from  the  same  parents.  Individuals 
are  the  units  of  organic  life,  forming  a  complete  ani- 
mate existence.  Peculiarities  of  races  or  breeds  are 
called  varieties.  Vegetables  and  animals  are  distin- 
guished from  each  other  by  the  term  Kingdom,  and 
the  types  in  each  kingdom  are  called  Sub-kingdoms. 

4.  The  names  which  naturalists  use  to  designate 
kinds  or  groups  of  living  things  are  formed  from  the 
Latin  or  the  Greek  language.  There  -are  good  rea- 
sons for  this.  In  the  modern  languages  common  things 
have  many  different  names.  But  the  majority  of 
plants  and  animals  are  new  or  rare,  and  have  no  name 
in  any  modern  language.  If  there  must  be  a  new 
name  it  may  as  well  be  Latin  or  Greek  as  any  other. 
Then  the  latter  languages  have  the  advantage  of  ex- 
pressing by  their  combinations  some  peculiarity  which 
is  distinctive,  and  which  is  readily  recognized  by  the 
learned.  As  to  the  difficulty  of  learning  these  terms, 
it  is  only  apparent.     They  can  easily  be  mastered  by 


26         Easy  Lessons  in  Vegetable  Biology. 

application.  The  terms  of  natuiftl  science  are  no  more 
difficult  than  those  of  geography  or  of  history. 

5.  The  types,  or  general  plans  of  structure,  found 
in  vegetable  Biology  may  be  described  briefly  as 
follows : 

1.)  Protophytes,  (Greek protos,  first,  and  phuton,  a 
plant.)  The  first  or  simplest  forms  of  plants — vege- 
tables composed  of  a  single  cell,  or  mass  of  bioplasm. 

2.)  Thallogens,  (Gr.  ihallus,  a  frond,  or  vegetable 
expansion,  and  ginomai,  to  produce  or  grow.)  Plants 
composed  of  a  tissue  of  cells,  or  bioplasts,  but  with  no 
clear  distinction  of  stem,  root,  and  leaves. 

3.)  Acrogens,  (Gr.  akra,  summit,  and  ginomai,  to 
grow.)  Plants  which  grow  at  the  summit  only,  and 
not  in  diameter. 

4.)  Endogens,  (Gr.  endon,  within,  and  ginomai,  to 
grow.)  Plants  whose  vessels  and  woody  libers  first 
grow  within  the  stem.  The  seed  has  but  a  single 
lobe,  or  cotyledon. 

5.)  Exogens,  (Gr.  exo,  outward,  and  ginomai,  to 
grow.)  Plants  whose  woody  fibers  grow  in  outer  lay- 
ers.    The  seed  has  two  lobes,  or  cotyledons. 

Under  these  five  types  or  plans  of  structure  all  the 
multitudes  of  plants  which  clothe  the  earth  or  dwell 
in  the  sea  can  be  arranged. 


Individual  Vegetable  Cells.  27 


CHAPTEE  V. 

individual  vegetable  cells. 

1.  The  elementary  masses  of  bioplasm  (Sec.  2,  Chap. 
II)  are  usually  called  cells,  even  if  they  are  merely 
pieces  of  animated  jelly,  uninclosed  by  an  outside 
shell  or  membrane.  Some  of  these  cells  remain  un- 
connected with  others  during  their  entire  life,  and 
multiply  by  self-division.  Others  have  a  living  or 
vital  connection  with  neighboring  cells,  so  as  to  form 
tissues  and  organs.  In  this  chapter  we  shall  consider 
the  vegetable  cell  as  an  individual — its  various  ap- 
pearances and  its  activities. 

2.  It  is  not  easy  to  distinguish  between  the  cell,  or 
living  matter,  of  an  animal  and  a  vegetable.  Some 
cells  appear  like  animals  at  one  part  of  their  lives  and 
like  vegetables  at  another  part.  After  long  study 
learned  naturalists  have  agreed  that  the  principal  dif- 
ference between  animals  and  plants  is  that  the  latter 
can  be  nourished  by  simple  mineral  or  chemical  (that 
is,  unorganized)  matter,  while  animal  nutrition  re- 
quires material  which  has  been  organized,  or  made 
part  of  a  living  being. 

3.  Most  vegetable  cells  produce  a  membrane,  or  cell- 
wall,  on  the  outside,  within  which  the  living  matter 


28        Easy  Lessons  m  Vegetable  Biology. 

is,  as  it  were,  imprisoned,  although  certain  openings, 
or  pores,  may  be  left  in  the  cell-wall  for  the  pur- 
pose of  communication.  There  is  also  a  concentra- 
tion of  living  matter  within  the  cell,  called  a  nucleus, 
and  sometimes  a  still  further  concentration  within  the 
nucleus,  called  a  nucleolus,  (or  little  nucleus.)  The 
bioplasm,  also,  within  the  cell,  differs  in  density,  that 
next  to  the  wall  of  the  cell  being  thicker,  or  more 
mucilaginous,  than  the  rest.  This  latter  part,  or  lay- 
er, has  been  called  the  primordial  utricle,  or  original 
bag.  Fig.  3  will  give  a  general  idea  of  the  element- 
ary vegetable  cell. 

4.  The  cell-wall  referred 
to  in  the  last  paragraph 
is  composed  of  a  substance 
somewhat  like  starch, 
called  Cellulose.  This  is 
often  thickened  by  de- 
posits inside,  layer  after 
Fig.  3.  layer.     When  it  becomes 

solid  it  is  known  as  woody  tissue.  Common  wood  is 
made  up  of  a  number  of  these  cells  arranged  side  by 
side. 

5.  In  cells  with  thin  membranes,  the  inherent  mo- 
tion of  the  bioplasm  (Chap.  Ill,  Sec.  2)  can  often  be 
seen  with  the  microscope.  This  motion  has  been 
called  circulation,  but  it  is  an  irregular  motion  of  the 
particles,  sometimes  slower,  sometimes  advancing,  now 


Individual  Vegetable  Cells. 


29 


retreating,  now  stopping,  or  beginning  again,  in  a 
way  differing  from  all  non-living  matter.    (Fig,  4.) 


Fiff.  4. 

6.  Sometimes  the  cell-wall  has  a  deposit  of 
material,  (silica})  or  of  other  mineral  matter, 
is  often  beautifully 
marked  with  lines  and 
dots.  Different  species  of 
plants  produce  different  pat- 
terns of  these  deposits,  as 
represented  in  the  figures  of 
Diatoms  in  Chap.  VII. 

7.  The  cell-wall  is  often  ir- 
regularly thickened  by  a  de- 
posit inside,  so  as  to  present 
different  appearances  in  (lif- 
erent cells.  In  the  Pine  and 
Fir  tribe  the  pores  in  the  wall 
of  the  wood-cells  are  sur- 
rounded by  concave  spaces 
or  depressions.     (Fig.  5.)  Fig.  5. 


flinty 
which 


30 


Easy  Lessons  m  Vegetable  Biology. 


In  other  cases  the  more  solid  matter  is  deposited  so 
as  to  form  dots,  or  rings,  or  spiral  fibers,  on  the  cell- 
wall.     (Figs.  6  and  7.) 


8. 


Fig.  6. 

Vegetable  cells  are  of 


according 


Fig.  7. 


various    shapes, 
to  the  purposes  which  they 
serve   or   the   pressure   to 
which  they  have  been  subjected.    They  may  be  glob- 
ular, oval,  conical,    prismatic,  cylindrical,  branched, 


Fig.  8.— Various  forms  of  cells :  a.  Conical,    b.  Oval.    c.  Prismatic,    d  Cylindric. 
€.  Sinuous.  /.  Branched,    g.  Entangled,    h,  Stellate,    i.  Fibro-cellular  tissue. 


Individual  Vegetable  Cells.  31 

star-shaped,  hour-glass  shaped,  disk-shaped,  tubular, 
many-sided,  or  of  any  other  form.     (Fig.  8.) 

9.  The  bioplasm  within  the  cell-wall  may  be  trans- 
formed into  a  great  variety  of  formed  material,  mak- 
ing special  cell-contents.  These  may  be  solid,  as  col- 
oring matter,  starch,  crystals,  and  resin ;  or  fluid,  as 
oil  and  gum,  or  solutions  of  sugar  or  tannin.  The 
most  important  of  these  substances  is  called  Chloro- 
phyll, (Gr.  chloros,  green;  phyllon,  a  leaf,)  or 
the  source  of  the  green  color  of  plants.  It  is  com- 
posed of  a  peculiar  coloring  matter  intimately  united 
with  separate  particles  of  bioplasm,  which,  under  the 
influence  of  sunlight,  causes  the  absorption  of  car- 
bonic acid  gas  from  the  air,  which  is  necessary  to 
nourish  the  plant.  Starch  is  also  an  important  prod- 
uct of  vegetable  cells,  even  more  widely  distributed 
than  chlorophyll.  It  seems  to  be  stored  up  in  the 
cells  as  a  reserve  food-material  for  the  use  of  the  new 
cells  which  are  subsequently  formed,  hence  it  oc- 
curs in  large  quantities  in  seeds, 
bulbs,  and  tubers.     (Fig.  9.) 

Crystals  of  oxalate  of  lime 
often  occur  in  cells,  as  well  as 
acid  substances  and  alkaloids, 
like  strychnine,  quinine,  etc., 
dissolved  in  the  cell-sap. 

It  is  remarkable  that  such 
different  materials  as  cellulose,  rig.  9. 


32 


Easy  Lessons  in  Vegetable  Biology. 


chlorophyll,  starch,  gum,  resin,  oil,  etc.,  may  be  pro- 
duced from  similar  cells  under  the  influence  of  the 
same  environment,  and  equally  exposed  to  heat, 
moisture,  and  electricity.     (Fig.  10.) 

10.  Cells  generate 
by  self -multiplication. 
One  will  divide  into 
two  or  more  pieces  of 
bioplasm,  which  wTill 
assume  the  form  and 
function  of  the  orig- 
inal cell  in  the  sim- 
pler forms  of  plants, 
or  may  take  a  dif- 
ferent shape  and  use 

Fig.  10.-*,  b  Cells  of  a  potato,  containing    fa    the     plant8    which 

etai-ch.     c.  Starch -grains  apart    d,  e,f.  Wheat-  r 

starch  in  different  positions.  are    COmpOSed    of    mi- 

merous  cells.  If  the  mother-cell,  as  it  is  called,  pos- 
sesses a  nucleus,  the  self -division  is  preceded  by  the 
formation  of  new  nuclei,  one  for  each  of  the  daugh- 
ter-cells. Sometimes  the  self -division  of  the  bioplasm 
is  produced  by  the  projection  of  a  sort  of  bud,  which 
is  separated  from  the  parent  mass.  If  the  newly- 
formed  cells  retain  a  vital  connection  with  each 
other,  cellular  structures,  or  tissues,  of  various  sorts 
are  produced.  The  most  complete  development  of 
this  kind  occurs  in  the  higher  types  of  plants. 


The  Cell  as  a  Member  of  a  Group. 


33 


CHAPTER  VI. 

THE  VEGETABLE  CELL  AS  A  MEMBER  OP  A  GROUP. 

1.  Only  a  comparatively  small  number  of  plants 
consist  of  a  single  cell.  These  are  the  simplest  forms 
of  plant  life.  In  the  greater  number  of  vegetables 
the  cells  are  united  into  groups.  Cell-families  may 
originate  from  a  single  mother-cell,  and  remain  for  a 
time  closely  connected,  or  contiguous,  yet  each 
daughter-cell  preserves  its  own  individuality,  and 
may  originate  a  new  colony.  Such  cell-families  only 
occur  in  the  lowest  classes  of  plants.  In  the  higher 
classes  the  union  of  cells  which  forms  tissues  and  or- 
gans is  permanent,  and  the  separate  cells  are  often  so 
closely  united  as  to  form  a  single  cavity  or  vessel; 
the  cell-walls  of  young  contiguous  cells  fusing  into  a 
common  mass,  or  cells  originally  distinct  uniting  in 
those  parts  of  the  walls  which  are  in  contact.  This 
union  is  so  strong  as  only  to  be  destroyed  by  chemical 
agents  which  dissolve  the  cell-wall.  Yet  sometimes 
cells  which  have  partially  united  separate  from  eacli 
other,  forming  a  cavity.  These  spaces  also  may  be 
grouped  together  so  as  to  form  passages,  or  air-canals. 

2.  The  woody  fibers  of  plants,  and  the  cellular 
tissue  which  makes  the  softer,  fleshy,  and  pithy  parts, 


34        Easy  Lessons  in  Vegetable  Biology. 

are  made  by  the  union  of  cells  into  groups.  Obser- 
vation has  shown  that  in  the  higher  plants  new- 
cells  are  not  produced  every-where  uniformly,  but  in 
particular  spots.  To  places  of  this  kind  the  terms 
growing-point  and  growing,  or  formative,  layer  have 
been  applied.  Growing-points  may  be  seen  in  the 
tips  of  buds,  and  formative  layers  between  the  wood 
and  bark  of  trees.  The  names  formative  or  generat- 
ing tissue  have  been  given  to  the  tissue  which  is  here 
formed  by  the  division  and  union  of  cells.  A  tissue 
in  which  the  cells  are  not  capable  of  self -division  is 
called  a  permanent  tissue. 

3.  In  direct  contrast  to  the  generating  tissues  are  the 
healing  tissues,  or  cork  tissues.  In  these  the  cells 
lose  their  cell-sap,  and  the  cellulose  of  the  walls  be- 
comes converted  into  cork,  which  is  of  great  im- 
portance as  the  true  healing  tissue  of  plants.  This  is 
formed  like  a  cushion,  or  callus,  over  the  surface  of 
a  wound  in  a  tree.  The  cuttings  of  the  cochineal 
cactus  would  decay  at  once  if  set  in  the  ground  with 
the  surface  of  the  wounds  fresh.  They  are  therefore 
laid  for  some  time  in  the  sun,  in  order  that  a  cork 
tissue  may  be  formed,  which  closes  the  wound  and 
prevents  decay.  Such  facts  not  only  prove  that  the 
living  vegetable  is  governed  by  other  than  invariable 
mechanical  forces,  but  are  also  mute  prophecies  of 
higher  truths  revealed  to  the  human  intelligence  in 
God's  word  relative  to  the  healing  of  the  soul. 


The  Cell  as  a  Member  of  a  Group. 


35 


4.  Vessels  are  made  by  the  union  of  several  cells,  the 
partition-walls  disappearing  while  the  union  continues 
at  the  margin.  Such  vessels  may  be  dotted,  reticula- 
ted, annular,  or  spiral,  from  the  deposit  on  the  cell- 
wall.     Chap.  V,  Sec.  7.     (See  Fig.  11.) 

^Bast-tubes,  or  bast- 
fibers,  are  long,  point- 
ed, thick- walled  tubes, 
commonly  united  into 
bundles.  In  hemp, 
flax,  etc.,  they  form 
textile  fibers,  and  they 
are  sometimes  united 
in  the  inner  layer  of 
bark  so  as  to  form  a 
kind  of  lace,  as  in  the 
lace-bark  of  the  West  Fig.  it, 

Indies.  Sieve-tubes,  or  bast-vessels,  result  from  the 
joining  of  cells  standing  one  above  the  other,  the 
partition-walls  of  which  have  become  perforated. 
Some  have  sieve-like  perforations  through  their  side 
walls. 

Other  vessels  are  simple  or  branched  tubes,  often 
making  a  net-work,  and  containing  a  sort  of  milky 
fluid  called  latex.  This  latter  contains  different  sub- 
stances in  different  plants,  as  gum,  resin,  opium,  in- 
dia-rubber, etc. 

5.  In  addition  to  the  groups  of  cells  which  form 


36 


Easy  Lessons  in  Vegetable  Biology. 


tissues  and  vessels,  other  smaller  groups  are  found, 
with  receptacles  formed  by  passages  between  the 
cells.  According  to  -  the  nature  of  the  substance 
secreted  these  spaces  are  called  oilpassages,  resin- 
passages,  camphor-glands,  resin-glands,  etc.  The 
term  nectaries,  or  honey-glands,  is  given  to  any 
part  of  a  flower  which  secretes  honey  or  sugary 
fluid. 

6.  The  first  independent  tissue  formed  in  flowering 
plants  by  the  union  of  cells  is  the  epidermis  or  skin. 
The  outer  layer  of  epidermal  cells  is  transformed  into 
a  thin,  structureless  membrane  called  the  cuticle. 
The  form  of  the  cells  varies  in  different  plants,  but 
they  are  usually  flat  or  tubular,  but  sometimes  pro- 
jecting like  little  knobs  or  bladders,  which  gives  a 
velvety  or  glistening  appearance  to  the  leaf  or  flower. 

Among  the  epider- 
mic cells  are  found 
pores,  each  of  which 
is  called  a  stoma,  or 
mouth.  (Plural,  sto- 
mata.)  These  are  in- 
closed by  two  or  four 
cells,  which  are  cres- 
cent-shaped, and  dis- 
tinguished from  other 
epidermal  cells  by 
their   smaller   size    and    by   containing   chlorophyll. 


Fig.  12. 


The  Cell  as  a  Member  of  a  Group.  37 

These  cells  are  thought  to  regulate  evaporation  by 
their  expansion.     (Fig.  12,) 

Hairs  are  epidermal  structures,  composed  of  one 
or  more  cells.  Under  this  general  term  may  be  in- 
cluded prickles,  scales,  stinging-hairs,  and  glands. 
Some  secrete  volatile  oil,  and  others,  as  the  nettle,  an 
acrid  fluid.     Fig.  13  exhibits  some  of  their  forms. 


Fig.  13. 

7.  Next  to  the  epidermis  we  find  the  cortex,  or 
bark,  often  composed  of  cells  containing  starch  or 
chlorophyll.  Yessels  containing  latex  (Sec.  4)  and 
glands,  as  well  as  sap-passages  between  cells,  may  also 
occur  in  it.  In  some  plants,  masses  of  cork  may  be 
found  in  the  bark  or  beneath  it.  In  such  the  outer 
parts  die  and  the  bark  peels  off. 

8.  Beneath   the   bark   is  the  formative  layer   or 


38 


East  Lessons  in  Vegetable  Biology. 


cambium,  (Sec.  2,)  in  which  thin-walled  cells  become 
transformed  into  vascular  or  bast-cells,  (Sec.  4,)  and 
these  are  changed  into  permanent  cells.  Groups 
of  cells  are  thus  formed  which,  united  into  bundles, 
penetrate  the  rest  of  the  tissue,  forming  the  fibro- 
vascular  bundles.  The  development  of  these  bundles 
is  characteristic  of  different  types  of  plants.  The 
simpler  types  have  no  fibro-vascular  bundles,  and  are 
called  Cellular  Plants  /  the  rest  are  termed  Vascular 
Plants. 

9.  The  fundamental  tissue  generally  consists  of 
thin-walled  cells  containing  starch,  although  other 
forms  of  cells  may  be  present.     In  plants  which  have 

no  fibro-vascu- 
lar bundles  the 
whole  interior 
may  be  regard- 
ed  as  funda- 
mental tissue. 
In  other  plants 
it  fills  up  the 
spaces  between 
the  bundles  and 
within  the  bark. 
In  the  type  of 
Endogens  (Ch. 
IY,  Sec.  5)  this  tissue  is  most  devexoped,  while  in  Ex- 
ogens  it  occupies  a  smaller  portion  of  the  structure. 


Fig.  14. 


The  Cell  as  a  Member  of  a  Group. 


39 


In  the  latter  it  generally  forms  a  central  pith,  con- 
nected  with  the  bark  by  more   or  less  developed 


Fig.  14*. 


portions  of  cellular  tissue, 
called  the  medullary  rays. 
(Figs.  14  and  14£.) 

10.  These  various  ele- 
ments of  plants,  consisting 
of  different  forms  of  cells, 
tissues,  and  fibro-vascular  bundles,  are  arranged  in 
each  species  in  a  characteristic  manner,  so  that  it  is 
often  possible  to  recognize  the  species  from  a  small 
fragment  of  the  plant.  For  this  purpose  small  trans- 
parent sections  of  a  stem  are  prepared,  cut  in  three 
different  ways — transversely,  longitudinally  through 
the  center,  and  a  section  parallel  to  the  last.  These 
are  mounted  on  glass  slips,  three  inches  long  by  one 
wide,  saturated  with  Canada  balsam  or  other  preserv- 
ative fluid,  and  covered  with  very  thin  glass  for 
microscopic  examination. 


40        Easy  Lessons  in  Vegetable  Biology. 


CHAPTEE  VII. 

PROTOPHYTES,  OR  THE  SIMPLEST  FORMS  OF  PLANTS. 

1.  The  simplest  form  of  individual  plant  life  is  a 
particle  of  living  matter  inclosed  in  a  membrane  or 
cell-wall.  Chap.  V,  Sec.  4.  Such  plants  are  called 
one-celled.  Some  of  these  remain  entirely  distinct 
from  other  cells,  others  form  cell-families  (Chap.  VI, 
Sec.  1)  in  a  sort  of  gelatinous  investment,  while 
other  kinds  form  a  sort  of  fiber  or  rod  by  the  adhesion 
of  cells  end  to  end.  As  each  cell  in  these  different 
kinds  is  capable  of  independent  life  and  growth  they 
are  all  classed  as  unicellular. 

2.  The  green  slime  which  grows  on  stones  or 
boards  in  damp  places  contains  many  of  these  one- 
celled  plants. 
One  of  the 
simplest  forms 
is  shown  in 
Fig.  15.  It  is 
often  found 
in  rain-water 
casks,  and  is 
called  the  Pro- 

Fig.  is.  tococcus — from 


Protophytes.  41 

two  Greek  words :  jprotos,  first,  and  coccus,  a  berry. 
Each  cell  is  round,  and  varies  in  color  from  bright 
green  to  bright  red,  according  to  the  nature  of  the 
coloring  matter  diffused  in  the  form  of  granules 
through  the  bioplasm.  It  requires  a  microscope  to 
see  the  form  and  structure  of  these  cells.  Each  cell 
is  a  perfect  plant,  and  like  all  vegetables  which  con- 
tain chlorophyll,  (Chap.  Y,  Sec.  9,)  under  the  influence 
of  sunlight,  breaks  up  the  carbonic  acid  gas  which  it 
absorbs  from  the  air,  retaining  the  carbon  and  giving 
off  the  oxygen.  In  the  dark,  however,  all  plants  ab- 
sorb ox}^gen  and  give  off  carbonic  acid,  rendering  it 
unsafe  to  have  many  plants  in  a  sleeping-room,  since 
carbonic  acid  gas  is  unfit  for  respiration  by  men  and 
animals. 

The  cell-wall  of  the  protococcus  is  quite  transpar- 
ent, and  if  burst  will  allow  the  bioplasm  and  the 
granules  of  red  or  green  chlorophyll  to  escape.  The 
cells  multiply  by  self -division,  each  one  producing 
two,  four,  eight,  or  sixteen  cells.  These  new  cells 
differ  from  the  parent  cell  in  not  remaining  quiet  or 
still,  but  having  the  power  of  active  movement. 
They  swim  about  like  animals  by  means  of  two  fila^ 
ments  or  cilia,  (Lat.  cilium,  an  eyelash.)  These 
moving  cells  may  also  subdivide  into  smaller  ones 
which  have  been  called  by  botanists  zoospores,  (Gr. 
zoos,  life,  and  sporon,  seed,)  or  living  seeds.  Many 
of  the   moving  cells,  however,  lose  their  cilia  and 


42        Easy  Lessons  in  Vegetable  Biology. 

become  stationary.  In  this  state  the  cell-wall  may 
thicken,  and  the  pond  where  it  dwells  dry  up,  but  the 
mass  of  bioplasm  in  the  cell  may  retain  dormant  life 
for  years,  and  be  ready  to  resume  its  work  as  soon  as 
moisture  and  warmth  shall  set  it  free. 

Many  of  these  resting  cells,  with  red  chorophyll, 
are  found  occasionally  in  the  snow  of  northern  re- 
gions, or  near  the  tops  of  high  mountains,  perhaps 


Fig.  16. 

carried  there  by  winds,  and,  finding  moisture  and  sun- 
light, multiply  themselves  so  rapidly  as  to  color  the 
snow  by  their  multitudes.  This  forms  what  is  known 
as  "Ked  Snow."  Similar  cells  may  grow  rapidly  in 
damp  places  and  form  masses  which  look  like  coagu- 
lated blood.  In  this  way  we  may  account  for  the  so- 
called  showers  of  blood  which  have  sometimes  alarmed 
the  superstitious. 

3.  Another  kind  of  primitive  plants  may  be  found 


Photophytes.  43 

as  green  fibers  or  threads  in  almost  every  running 
stream.  The  microscope  will  show  the  cells  of  these 
fibers  applied  end  to  end— the  cells  at  each  end  mul- 
tiplying by  self-division.  In  another  kind,  adjacent 
cells  grow  together,  and  the  green  chlorophyll  and 
bioplasm  mix  in  one  of  the  cells,  forming  a  sort  of 
spore,  or  seed,  which  produces  a  new  filament  by  cell- 
division.     (Fig.  16.) 

4.  The  unicellular  plants  most  interesting  to  those 
who  study  with  the  microscope  are  called  Diatoms, 
(from  two  Greek  words  signifying  to  cut  through,) 
because  of  the  ease  with  which  a  chain  of  them  may 
be  broken  up  into  individual  cells.  These  cells  con- 
tain chlorophyll,  generally  of  a  brownish  color,  and 
the  external  membrane,  or  cell- wall,  is  hardened  by  a 
deposit  of  flinty  matter.  There  are  many  kinds  of 
Diatoms,  with  flinty  shells,  beautifully  marked  with 
lines  and  dots,  often  surpassing  the  most  complicate 
patterns  of  art.  Some  are  globular  in  shape,  some 
flat  with  sides  like  a  pill-box,  others  square,  triangu- 
lar, boat-shaped,  etc.  They  move  about  in  the  water, 
so  that  some  have  thought  them  to  be  animals.  Many 
are  so  minute  as  to  require  the  very  finest  micro- 
scope to  make  out  their  details.  Each  cell  consists  of 
two  valves,  or  plates,  applied  together  like  the  valves 
in  a  muscle-shell.  Fig.  17  shows  a  valve  of  one  of 
the  most  ornamental  diatoms— the  Arachnoidiscns 
EJirenhergii.     The  first  of  these  words  signifies  a  disk 


44 


Easy  Lessons  in  Vegetable  Biology. 


built  like  a  spider's  web,  and  is  applied  to  the  genus. 
The  second  word  refers  to  the  name  of  a  distinguished 


Fig.  17. 

naturalist,  and  names  the  species — the  Arachnoidiscus 
of  Ehrenberg.  This  example  illustrates  how  the  vari- 
ous kinds  of  organisms  are  named. 

In  Fig.  18  there  are  examples  of  three  other  kinds 
of  diatoms. 

In  the  living  state  diatoms  are  found  abundantly  in 
every  pond,  rivulet,  ocean,  and  rock-pool.  They 
often  make  immense  deposits  by  their  rapid  multi- 
plication, and  in  a  fossil  state  they  form  large  strata 
of  rock  material.     Under  the  cities  of  Richmond  and 


Protophytes. 


45 


Petersburg,  in  Virginia,  is  such  a  stratum  20-40  feet 
thick. 

5.  Each  kind,  or  species,  of  unicellular  plants,  like 
every  other  organic  form,  has  endowments  or  in- 
stincts of  its  own.     One  sort  remains  a  rounded  cell, 


Fig.  18. 


or  changes  to  a  motile  one.  Another  becomes  elon- 
gated, and  distributes  its  coloring  matter  inside  in 
spiral  form.  Others  appropriate  glassy  flint  from 
their  food,  and  deposit  it  in  beautiful  patterns  upon 
their  outer  cell-wall.  Each  cell,  however,  in  this  type 
of  Protophytes  is  capable  of  independent  life  apart 
from  the  rest,  and  may  be  considered  as  a  complete 
individual. 


46        Easy  Lessons  in  Vegetable  Biology. 


CHAPTER  VIII. 

THALLOGENS,  OR  DIVISION  OF  LABOR  IN  PLANTS. 

1.  In  the  plants  which  we  have  been  considering 
each  cell  is  an  individual,  but  in  all  other  kinds  the 
plant,  or  individual,  is  made  up  of  many  cells,  each 
one  of  which  has  a  special  work  to  do.  Some  belong 
to  the  root,  some  to  the  axis,  or  stem,  and  others  to 
the  leaves,  flowers,  or  seeds.  In  the  type  of  Thal- 
logens  there  is  no  very  accurate  division  of  root,  stem, 
leaves,  and  flowers,  and  the  whole  plant  is  called  a 
thallus,  a  frond,  or  green  expansion.  Under  this 
type  we  find  the  classes  of  Algce,  or  Sea-weeds; 
Lichens,  or  the  dry,  leafy,  or  mossy  patches  on  trees, 
stones,  etc. ;  and  Fungi,  or  mushrooms,  molds,  and 
their  allies. 

2.  The  Algce,  or  Sea-weeds,  have  been  divided 
into  three  orders,  the  Red,  the  Olive,  and  the  Green 
sea-weeds.  In  the  more  complicate  forms  we  find  a  > 
sort  of  distinction  of  root,  stem,  and  leaf,  which  re- 
minds us  of  still  higher  plants,  but  the  distinction  is 
more  apparent  than  real,  since  the  root  and  stem 
serve  little  other  use  than  the  mere  mechanical  at- 
tachment of  the  plant.  The  whole  plant  is  made  up 
of  cells,  and  there  are  no  proper  vessels.     Chap.  VI, 


Thallogens.  47 

Sec.  4.  These  external  resemblances  seem  uncon- 
scious prophecies  of  forms  which  prove  that  all  living 
things  have  been  formed  upon  an  intelligent  plan. 

The  cells  of  algce  multiply  by  self-division,  and  are 
of  various  forms.  Some  absorb  nourishment,  or 
secrete  various  materials,  or  serve  merely  for  growth, 
while  others  are  appropriated  to  the  reproduction  of 
the  species,  which  in  some  instances  has  a  very  com- 
plicated method. 

3.  The  class  of  Fungi  contains  a  large  number  of 
different  kinds,  some  quite  simple  and  others  complex 
in  structure.  These  organisms  have  so  many  pecul- 
iarities that  some  scientists  regard  them  as  neither 
animal  nor  vegetable,  but  as  forming  a  sort  of  third 
kingdom.  They  have  a  similar  cellular  form  to  vege- 
tables, but  they  have  no  chlorophyll,  as  green  vegeta- 
bles have ;  light  is  not  necessary  to  their  growth  as  it  is 
to  vegetables ;  and,  like  animals,  they  need  organic  sub- 
stances for  food.  It  has  been  found  that  they  are  the 
agents  of  fermentation  and  putrefaction,  and  their  prin- 
cipal business  seems  to  be  the  removal  of  the  waste  ma- 
terial of  both  animal  and  vegetable  life.  They  are 
universal  scavengers.  The  simplest  forms  of  Fungi, 
or  the  Molds,  resemble  Protophytes,  except  in  the  ab- 
sence of  chlorophyll.  The  yeast-plant  is  one  of  these 
forms.  It  is  simply  a  round  or  oval  cell  which  mul- 
tiplies rapidly  by  putting  forth  buds  and  by  self -di- 
vision.    It  is  the  cause  of  fermentation  in  all  sugary 


48        Easy  Lessons  in  Vegetable  Biology. 

solutions.  Bacteria  of  different  kinds  are  minute 
fungi,  similar  to  the  yeast-plant,  but  living  in  solu- 
tions of  animal  matter,  in  which  their  growth  causes 
putrefaction.  Recent  studies  render  it  likely  that  the 
more  simple  forms  are  but  imperfectly  developed 
stages  in  the  life-history  of  other  kinds.  Fig.  19 
shows  the  appearance  of  bacteria  when  greatly  mag- 
nified. All  fungi  are  made  up  of  elongated  cells, 
sometimes  branching  and  sometimes  membranous  or 


riii      11  — \ — r 


At 


^ 


Fig.  19. 

pulpy,  forming  a  mycelium,  or  spawn,  and  rounded 
cells  forming  spores,  or  seeds,  which  may  be  supported 
on  filaments  or  contained  in  sacs.  The  common 
mushroom  is  one  of  the  larger  fungi,  and  the  white 
or  green  mold  on  preserves,  cheese,  etc.,  an  example 
of  the  minuter  kinds. 

Many  diseases  of  plants  and  animals  are  associated 
with  the  presence  of  fungi.  Mildew  and  rust  in 
wheat,  the  potato-blight,  the  false  membrane  in  diph- 
theria, and  many  other  evidences  of  diseased  action, 


Thallogens.  49 

seem  to  depend  upon  the  growth  of  these  parasites. 

In  many  cases,  however,  it  is  not  fully  ascertained 

whether  the  hacteria,  or  other  fungus,  is  the  cause  of 

the  diseased  condition,  or  is  present,  because  of  the 

disease,  to  remove  the  decaying  material. 
4 


50 


Easy  Lessons  in  Vegetable  Biology. 


CHAPTEE  IX. 

ACROGENS,  OR  PLANTS  WHICH  G&OW  AT  THE  SUMMIT. 

1.  In    fresh-water  ponds  and   rivers,  growing  in 
tangled  masses  of  a  dull  green  color,  we  may  often 


Fig.  20. 


find  plants  with  stems  about  as  thick  as  a  stout  needle, 
but  perhaps  three  or  four  feet  long,  with  branchlets 
(improperly  called  leaves)  arranged  in  whorls  at  regu- 
lar intervals  upon  the  axis.    These  are  the  stone-worts, 


AcROGENS. 


51 


consisting  of  two  genera,  Cham  and  Nitella.  In 
the  latter  the  stem  is  a  simple  tube,  but  in  Chara  the 
central  or  axial  cell  is  surrounded  in  a  spiral  manner 
by  others.  In  Chara,  also,  the  stem  is  incrusted  by 
carbonate  of  lime.  Fig.  20  will  sufficiently  illustrate 
their  forms.  The  points  on  the  axis,  or  stem,  from 
which  the  branchlets  spring,  are  called  nodes,  and  the 
intervening  parts  are  the  internodes. 

These  stone-worts  illustrate  the  manner  of  growth 
in  the  type  of  Acrogens.  Each  internode  is  formed 
by  the  growth  and  elongation  of  single  cells.  The 
terminal  bud  is  also  formed  by  a  single  cell,  which 
subdivides  into  two.  One  of  the  latter  forms  the  in- 
ternode, while  the  other  subdivides  into  lateral  cells, 
which  by  continual  division  produce  the  branchlets. 
After  a  time  the  terminal  cell  in  the  latter  is  incapa- 
ble of  further  division,  but  in  the  stem  the  process 
continues  indefinitely.     (Fig.  21.) 

These  stone-worts  are 
also  reproduced  by  cer- ' 
tain  organs  which  grow 
at  certain  parts  of  the 
axis.  These  organs  are 
of  two  kinds,  oval  spor- 
angia, or  spore-fruits, 
and  antheridia,  or  or- 
gans which  contain  fila- 
ments corresponding  to     __  Fig.  21. 


52        Easy  Lessons  in  Vegetable  Biology. 

the  anthers,  or  male  organs,  of  flowering  plants.  The 
cells  of  each  antheridium  contain  little  swimming 
bodies  called  antherozoids,  (living  anthers.)     (Fig.  22.) 

These  coiled  up  anther- 
ozoids  twist  and  turn  about 
until  they  escape  from  the 
cell  and  swim  in  the  fluid 
by  means  of  their  two  cilia. 
They  find  their  way  to  the 
spore-cases,  and  by  coales- 
cence form  the  oospore,  (the 
egg-spore,  or  embryo,)  from 
which  the  future  plant  is 
Fig.  22.  derived.    When  we  consider 

the  power  of  motion  in  these  organs  and  others  simi- 
lar to  them,  we  are  obliged  to  admit  that  sharp  lines 
of  distinction  between  plants  and  animals  are  impos- 
sible in  these  apparently  simple  forms.  The  growing 
spore  of  the  stoneworts  gives  off  two  filaments,  one 
of  which  serves  as  a  temporary  root,  while  a  cell  in 
the  other  produces  a  group  of  lateral  projections  from 
which  the  young  plant  springs.  This  temporary 
structure  is  termed  the  pro-embryo,  and  something 
similar  to  this  is  common  to  all  the  Acrogens. 

2.  Ferns  form  another  family  of  Acrogens,  or  sum- 
mit-growers. Their  various  species  are  admired  for 
their  beautiful  fronds,  often  improperly  called  leaves, 
and  books  of  collectors  often  grace  the  parlor  table. 


ACROGENS.  53 

They  vary  in  size,  from  the  Tree-ferns  of  the  tropics, 
which  may  be  fifty  or  sixty  feet  high,  to  the  delicate 
Maiden-hair  fern  of  the  shady  dell.  In  temperate 
climes  ferns  have  usually  a  simple  or  branched  un- 
der-ground stem,  called  a  rhizome ^  a  root-stalk,  from 
which  grow  root-hairs  and  fronds.  The  epidermis  of 
the  stem  is  of  brownish  hue,  and  when  young  and 
above  ground  is  provided  with  stomata.  Chap.  VI, 
Sec.  6.  As  in  higher  plants,  the  general  cellular 
structure   consists   of    many-sided    cells,    containing 


Fig.  23. 

chlorophyll  and  starch  granules.  There  are  also  ves- 
sels, (annular,  spiral,  and  scalariform,  or  ladder-like,) 
and  fibrous  or  woody  tissue,  together  forming  the 
harder  tissues. 

Fig.  23  illustrates  the  growth  of  a  fern  at  the 
summit,  together  with  the  metamorphosis  of  the  ter- 
minal cell  into  the  various  tissues. 

In  flowering  plants  the  terminal  cell  of  the  leaf -bud 
becomes  barren,  and  the  enlargement  of  the  leaf  de- 
pends   on   the    multiplication   and   growth  of  cells 


54         Easy  Lessons  in  Vegetable  Biology. 

nearer  the  base,  but  in  the  fern  the  frond  grows  as 
the  stem  does,  so  that  the  peduncle,  or  stalk,  is  first 
formed,  then  the  embryo  frond,  then  the  pinnules,  or 
wings,  etc. 

Underneath  the  frond  of  a  fern  we  may  sometimes 
see  little  brown  patches.  Each  patch  is  called  a  sorus, 
(plural,  sori.)  It  is  sometimes  covered  by  a  mem- 
brane called  an  indusium,  and  the  little  brown  bodies 
constituting  it  are  spore-cases  which  have  been  de- 
veloped from  epidermal  cells.  An  elastic  ring  sur- 
rounds each  spore-case  and  assists  in  opening  it.  The 
growth  of  the  minute  spores  in  the  spore-cases  may  be 
watched  from  time  to  time  under  the  microscope. 
The  little  spore  swells  and  bursts,  and  sends  out  a 
rootlet  into  the  soil.  Then  a  number  of  delicate  cells 
are  formed  from  the  mother-cell  in  the  spore,  making 
a  little  green  scale,  which  throws  out  rootlets  on  its 
under  side.  This  jprothallium  (as  it  is  called)  pro- 
duces two  kinds  of  cells,  one  set  which  contains  spiral 
filaments  which  escape  and,  by  apparently  spontane- 
ous movements  enter  the  others,  or  germ-cells,  from 
which  the  future  fern  is  produced.  Fig.  24  gives 
a  good  representation  of  the  various  parts  in  the 
structure  and  life-history  of  a  fern. 

3.  Mosses  are  also  examples  of  plants  which  grow 
at  the  tip,  or  summit.  They  are  minute  and  lowly 
plants,  but  are  by  no  means  insignificant.  They  have 
distinct  axes  of  growth,  and  their  delicate  leaves  are 


AcEOGENS. 


55 


arranged  with  great  regularity.  The  stem  shows  some 
indication  of  the  separation  of  a  bark-like  portion 
from  the  pith-like,  by  the  intervention  of  a  circle  of 
bundles  of  elongated  cells,  from  which  branches  pass 
into  the  leaves,  so  as  to  afford  them  a  sort  of  midrib. 


Fie.  24. 


The  root-fibers  are  long,  tubular  cells,  quite  trans- 
parent, within  which  the  circulation  of  bioplasm  may 


be  seen. 


56 


Easy  Lessons  in  Vegetable  Biology. 


The  stems  of  mosses  usually  terminate  in  filaments, 
each  supporting  an  urn-shaped  vessel  closed  by  a  lid. 
The  urn  is  covered  by  a  cap,  or  hood.  Under  the  lid 
the  edge  of  the  urn  has  a  toothed  fringe,  and  within 
the  urn,  or  spore-capsule,  are  double-coated  spores. 
(Fig.  25.) 


Fig.  25. 


In  producing  new  plants,  the  outer  coat  of  the 
spore  bursts  and  the  inner  wall  protrudes.  New  cells 
grow  from  the  extremity,  forming  a  filament,  whose 
cells  at  certain  points  multiply  by  subdivision,  so  as 
to  form  rounded  clusters,  from  each  of  which  an  in- 
dependent plant  may  arise. 

The  minuteness  of  the  spores  of  mosses  and  similar 
plants  accounts  for  their  general  distribution,  even  in 


ACROGENS.  57 

the  most  distant  and  barren  places.  Bare  rocks  raised 
from  the  bottom  of  the  sea,  and  lava-flows  from  the 
tops  of  volcanoes,  marshes  and  dry  mountain-tops,  are 
soon  covered  by  mosses  and  their  allies. 


58        Easy  Lessons  in  Vegetable  Biology. 


CHAPTER  X. 

ENDOGENS,   OR  INSIDE-GROWERS. 

1.  Grasses,  rushes,  lilies,  and  palms,  with  similar 
families  of  plants,  are  found  in  the  type  of  Endogens, 
Chap.  IV,  Sec.  5.  This  term  was  given  to  them 
because  it  was  thought  that  their  woody  and  vascular 
fibers  grew  from  the  inside,  and  pushed  the  earlier- 
formed  bundles  of  fibers  toward  the  circumference 
of  the  stem.  More  exact  examinations  have  shown 
that  the  fibro-vascular  bundles  grow  within  the  cellu- 
lar or  fundamental  tissue,  turn  first  inward  toward 
the  center  or  pith,  and  then  bend  outward  and  pass 
into  the  leaves.  In  grasses  the  cells  of  the  center  dis- 
appear except  at  the  nodes,  (Chap.  IX,  Sec.  1,)  leav- 
ing the  stem  hollow. 

2.  Endogens  are  often  called  Monocotyledons, 
(Greek  monos,  one,  and  Tcotyledon,  a  seed-lobe,)  be- 
cause the  young  plant  has  but  a  single  seed-lobe. 
Exogens  have  two  seed-lobes,  as  we  may  see  in  a 
sprouting  bean  or  pea,  and  are  called  Dicotyledons, 
(Gr.  dis,  two.)  Acrogens  and  Thallogens  have  no 
seed-lobe  at  all,  but  are  propagated  by  cellular  spores, 
and  are  called  Acotyledons,  (Gr.  a,  without.) 

3.  In  Endogens  and  Exogens  we  find  a  more  com- 


Endogkns. 


5f> 


plete  development  of  the  root,  stem,  and  leaves  than 
in  the  other  types,  giving  a  character  to  the  external 
form  of  plants  which  enables  us  to  recognize  them 
and  place  them  in  a  natural  system  of  classification. 
It  is  therefore  appropriate  here  to  consider  these 
structures  in  as  brief  and  comprehensive  manner  as 
possible. 

4.  If  a  pea  or  bean  be  soaked  in  water,  and  the 
leathery  skin  be  stripped  off,  two  large  fleshy  masses 
will  be  seen  (the  cotyledons)  inclosing  a  small  cylin- 
drical body,  (the  axis,)  which  bears  two  minute  leaves 

at  its  extremity.     The  cotyledons  and  axis  together 

constitute  the  embryo. 

In  the  growing  plant 

the    stem  grows   from 

the    axis  upward   and 

the  root  downward, 

and  the  leaves  develop 

only  on  the  ascending 

part  of  the  axis  and  not 

on  the  root. 

In  the  growing  stem 

the   terminal  cells  (#, 

Fig.   26,    A)  multiply 

and  enlarge.    They  fur- 
nish new  cells  to  the 

cambium  layer,  or  that 

between  the  bark  and 


FJg.2C. 


60         Easy  Lessons  in  Vegetable  Biology. 

wood  of  Exogens.  Chap.  VI.  Sec.  8.  In  the  root, 
the  multiplying  cells  are  not  quite  at  the  extremity. 
A  sort  of  cap  is  formed,  which  receives  additions  to 
its  interior  and  pushes  out  the  layers  external  to 
them.  Thus  the  new-formed  tissue  is  protected  from 
the  rough  soil.  (Fig.  26,  B,  C.)  Sometimes  the  ab- 
sorbing activity  of  the  points  of  the  root-hairs  is  so 
great  that  particles  of  soil  actually  unite  with  them, 
to  be  afterward  dissolved  by  the  cell-sap. 

5.  The  primary  root  is  that  which  is  formed  by 
the  downward  elongation  of  the  axis.  It  is  in  a  line 
with  the  stem.  It  is  called  a  tap-root  when  it  is 
thicker  than  the  branches  which  spring  from  it,  and 
may  be  fusiform  or  spindle-shaped  like  the  carrot, 
napiform  or  turnip-shaped  as  the  radish  or  turnip, 
filiform  or  threadlike,  or  cylindrical.  Secondary  or 
lateral  roots  are  those  which  spring  laterally  from  the 
stem  or  primary  root,  as  the  clasping  roots  of  ivy. 
Sometimes  the  primary  root  is  undeveloped,  or  dies, 
and  is  replaced  by  secondary  roots.  In  grasses  these 
are  filiform,  and  are  called  fibrous  roots.  Sometimes 
secondary  roots  become  tuberous  or  fasciculated, 
(swollen  in  the  middle,  or  at  intervals,)  as  in  the 
dahlia,  etc.  All  roots  are  more  or  less  branched,  and 
are  covered  with  delicate  root-hairs.  If  the  branches 
of  the  root  run  near  the  surface  of  the  ground,  they 
are  called  creeping  roots. 

6.  The  stem  is  that  part  of  the  plant  which  bears 


Endogens.  01 

the  leaves,  flowers,  and  fruit.     Some  plants  are  ap- 
parently  stemless,   from  this    part   remaining  very 
short  and  undeveloped  in  proportion  to  the  roots  and 
leaves,  as  in  the  primrose.     The  woody  stem  or  trunk 
characterizes  trees  and  shrubs.     A  simple  unbranched 
trunk,  as  the  palm,  is  called  a  candex.     The  scape  is 
a  leafless  stem  bearing  only  flowers,  and  belonging  to 
a  so-called  stemless  plant.     It  may  bear  only  a  single 
flower,  as  the  tulip,  or  several,  as  the  hyacinth  and 
lily  of  the  valley.     Sometimes  stems  send  out  run- 
ners or  branches  which  run  above  the  ground,  and 
send  out  adventitious  roots  from  their  nodes  or  ex- 
tremities which  develop  perfect  plants,  as  the  straw- 
berry.    The  rhizome  is  an  under-ground  stem,  send- 
ing up  branches  into  the  air.     The  tuber  is  a  thick- 
ened, fleshy  under-ground  stem,  as  the  potato,  in  which 
we  may  find  buds  or  eyes  concealed  in  depressions. 
The  lull  is  also  fleshy,  but  has  scales  surrounding  the 
solid  base  or  •dish  of  the  stem,  or  attached  to  its  apex. 
"When  the  disk  is  large  and  surrounded  by  only  a  few 
leaves,  as  in  the  crocus,  it  is  called  a  corm.    Bulbs 
may  be  squamose  or  scaly,  tunicated  as  in  the  onion, 
fibrous,  etc. 

The  length  of  life  of  the  stem  and  roots  may  be 
only  a  single  year,  or  annual;  two  years,  or  liennial; 
or  a  number  of  years,  or  perennial. 

The  trunk  or  woody  stem  of  Exogens,  or  outside- 
growers,  shows  on  a  transverse  section  a  number  of 


62        Easy  Lessons  in  Vegetable  Biology. 

circles  of  fibro- vascular  bundles,  with  cellular  rays 
passing  from  the  pith  to  the  bark.  Chap.  VI,  Sees. 
9, 10.  These  circles  are  supposed  to  indicate  the  layers 
of  annual  growth,  but  this  is  quite  uncertain.  Some- 
times two  or  more  circles  are  formed  in  a  year.  The 
diameter  and  height  attained  by  some  E^xogens  may 
be  very  great.  The  Big-Tree  Grove,  in  Calaveras 
County,  California,  contains  trees  from  350  to  400 
feet  high,  and  33  feet  in  diameter. 

The  stems  of  Endogens,  or  inside-growers,  exhibit 
in  their  sections  no  distinct  pith,  no  concentric  circles, 
no  medullary  rays,  and  no  separable  bark. 

7.  Stems  produce  buds,  which  may  be  regarded  as 
shortened  axes,  capable  of  elongation.  According  to 
the  organs  which  result  from  their  development,  they 
are  termed  stem-buds,  leaf -buds,  and  Jtoicer-buds. 
They  are  terminal  if  produced  at  the  extremity  of 
the  primary  axis,  and  lateral  if  at  the  sides  of  the 
axis.  In  palms  and  tree-ferns  the  bufls  are  termi- 
nal, and  if  the  top  of  the  stem  is  cut  off  the 
plants  perish.  Buds  are  often  protected  by  coarse 
leaves  or  scales,  which  may  be  covered  with  hairs, 
or  with  gummy  or  resinous  matter  for  additional  pro- 
tection. 

Buds  often  lie  dormant,  and  do  not  appear  as 
branches  unless  stimulated  by  some  local  injury  to  the 
plant ;  others  are  altered  into  thorns.  Thorns  are 
undeveloped  branches,  and  many  plants  which  are 


Endogens.  63 

thorny  when  wild  are  not  so  nnder  cultivation. 
Thorns  differ  from  prickles,  which  are  hardened 
hairs. 

8.  Lewes  are  constituted  of  cells,  with  cavities, 
fibro-vascular  bundles,  and  epidermis.    (Fig.  27.) 


Fig.  27. 

The  veins  in  a  leaf  are  the  vascular  parts,  and  their 
distribution  differs  in  the  types  of  Endogens  and 
Exogens,  so  as  to  afford  a  ready  means  of  discrimina- 
tion. The  veins  in  the  leaves  of  Endogens  are  gen- 
erally parallel  or  straight,  and  do  not  form  a  network 
as  in  Exogens.     (Fig.  28.) 

When  two  leaves  are  at  the  same  level,  one  on  each 
side  of  the  stem,  they  are  called  opposite;  when  a 
circle  of  leaves  is  thus  produced  it  is  called  a  whorl. 
When  there  is  only  one  leaf  on  the  same  level  the 


G4        Easy  Lessons  in  Vegetable  Biology. 


leaves  are  alternate  or  scattered.  Irregular  as  the 
latter  mode  may  appear  in  different  plants,  observa- 
tion shows  that  it  is  tolerably  uniform  in  each  species. 
If  a  spiral  line  (or  thread)  is  drawn  round 
the  stem  connecting  the  points  of  attach- 
ment of  the  leaves,  and  these  are  marked 
on  the  spiral,  it  is  found  that  in  any  par- 
ticular species  there  is  a  definite  number 
of  leaves  on  any  given  number  of  turns 
made  by  the  spiral  round  the  stem.  In 
the  peach  and  plum  the  cycle  made  by 
the  leaves  directly  above  each  other  em- 
braces five  leaves,  and  the  spiral  goes 
twice  round  the  branch.  This  is  expressed 
by  the  formula  £,  In  the  alder  three 
leaves  form  the  cycle,  and  the  spiral  has 
but  a  single  turn  on  the  stem.  This  is 
represented  by  the  fraction  £. 

Covering-leaves  are  so  called  because 
they  cover  or  protect  other  parts,  as  the 
scales  of  buds,  and  bracts,  or  leaves  in 
axils  of  which  flowers  are  placed.  The 
leaf-stalk  is  called  a  petiole.  When  it  is 
absent  the  leaf  is  said  to  be  sessile.  At 
the  base  of  the  petiole  flat  leaf-like  ap- 
pendages are  often  found,  called  stipules. 

Leaves  are  said  to  be  sinvple  when  the  blade  is 
composed  of  one  piece,  however  irregular  may  be  its 


Fig.  28. 


Endogens.  65 

shape,  and  compound  when  divided  into  distinctly 
separate  parts,  or  leaflets,  connected  with  the  petiole 
by  secondary  petioles. 

Leaves  may  be  lanceolate,  or  narrow  and  tapering; 
oblong,  or  narrow  and  not  tapering ;  cordate,  or  heart- 
shaped;  sagittate,  or  arrow-shaped;  ovate,  or  egg- 
shaped,  etc.  A  compound  leaf  having  leaflets  placed 
laterally  is  called  pinnate.  If  the  leaflets  are  them- 
selves divided,  it  is  bipinnate,  and  a  further  division 
of  the  leaflets  is  tripinnate.  Sometimes  a  compound 
leaf  is  triple,  or  ternate,  etc.  When  a  ternate  leaf 
divides  twice  it  is  biternate  ;  when  thrice,  triter- 
nate. 

It  is  not  uncommon  to  find  on  the  same  plant  leaves 
of  different  forms.  The  radical  leaves,  or  those 
which  grow  from  the  lower  part  of  the  stem,  are  often 
different  from  the  upper  ones. 

The  function,  or  use,  of  leaves  is  to  expose  the 
juices  of  the  plant  to  light  and  air,  and  thus  aid  in 
forming  the  woody  matter  of  the  stem  and  the  vari- 
ous secretions.  If  the  leaves  are  excluded  from  air 
and  light,  as  is  the  case  in  crowded  plantations,  the 
wood  is  not  properly  formed.  The  same  may  be  said 
of  all  the  substances  formed  by  the  plant.  Thus, 
potatoes  grown  in  the  shade,  which  impedes  the  ac- 
tion of  the  leaves,  become  watery,  and  produce  little 
starch  in  their  tubers. 

Leaves  also  exhale  watery  fluid,  and  by  decompos- 
5 


66        Easy  Lessons  in  Vegetable  Biology. 

ing  carbonic  acid  gas  are  able  to  appropriate  the  car- 
bon as  food,  and  return  the  oxygen  to  the  air.  Chap. 
V,  Sec.  9. 

The  length  of  life  of  leaves  varies  greatly.  In 
temperate  climates  the  majority  of  leaves  fall  off  in 
the  autumn,  or  are  deciduous.  In  the  so-called  ever- 
green trees  and  shrubs  they  persist  through  the  win- 
ter, and  may  even  remain  several  years. 

9.  The  root,  stem,  and  leaves  of  a  plant  constitute 
its  organs  of  nutrition.  Fluid  matters  are  taken  up 
from  the  soil  by  the  cells  of  the  roots,  these  are  con- 
veyed to  the  leaves,  and  under  the  influence  of  air  and 
light  are  fitted  for  the  purposes  of  plant  life,  and  for 
the  production  of  various  materials,  as  starch,  gum, 
sugar,  woody  matter,  gluten,  oils,  and  resins.  Chap. 
V,  Sec.  9. 

10.  The  flower  is  the  organ,  or  assemblage  of  or- 
gans, for  the  production  of  the  seed.  In  Endogens 
and  Exogens  this  structure  is  conspicuous,  and  they 
are  hence  called  flowering  plants,  to  distinguish  them 
from  other  types. 

Fig.  29  illustrates  the  general  structure  and  ar- 
rangement of  parts  in  a  flower.  The  poet  Goethe 
taught  that  all  the  various  parts  of  a  plant  are  modi- 
fications of  leaves.  Not  that  they  wrere  originally 
leaves  and  were  transformed,  but  that  they  are  formed 
of  the  same  elements,  arranged  upon  the  same  plan, 
and  follow  the  same  general  laws  as  leaves.     The 


Endogens. 


67 


parts  of  a  flower  are  lience  called  floral  leaves.    These 
are  usually  arranged  in  four  whorls.     The  outer  whorl 


Fig.  29. 


is  the  calyx,  the  next  the  coroUa,  the  third  the  sta- 
mens, and  the  innermost  the  pistil. 


G8         Easy  Lessons  in  Vegetable  Biology. 

The  flowers  of  Exogens  exhibit  two  Or  five  parts, 
or  multiples  of  these  numbers,  in  their  whorls,  while 
Endogens  have  three,  or  a  multiple  of  three,  in  their 
whorls.  In  Exogens,  also,  the  calyx  is  usually  green 
and  the  corolla  colored,  but  in  Endogens  both  are  often 
colored.  The  term  perianth  is  generally  applied  to 
the  floral  envelopes  of  Endogens. 

The  parts  of  the  calyx,  when  separate,  are  called 
sepals,  and  the  leaves  of  the  corolla  petals.  Stamens 
have  two  parts,  the  filament,  or  stalk,  and  the  anther, 
or  broader  portion,  corresponding  to  a  folded  leaf,  and 
containing  fertilizing  grains  called  pollen.  The  pistil 
is  also  made  up  of  two  parts,  the  ovary,  containing 
ovules,  or  young  seeds,  and  the  stigma  for  the  recep- 
tion of  the  pollen-grains.  This  latter  is  sometimes 
sessile,  or  resting  on  the  ovary,  and  sometimes  ele- 
vated on  a  stalk,  or  style. 

Some  flowers  have  no  stamens,  and  are  called  fe- 
male flowers;  others  have  no  pistils,  and  are  male 
flowers.  But  these  organs  are  always  present,  either 
on  the  same  plant  or  on  different  plants.  If  the  co- 
rolla is  absent  the  flower  is  called  incomplete,  and  if 
corolla  and  calyx  are  both  absent  it  is  naked.  The 
position  of  the  stamens  in  relation  to  the  ovary  is  of 
botanical  importance.  Sometimes  they  are  attached 
to  the  receptacle,  or  upper  part  of  the  flower-stalk. 
They  are  then  below  the  ovary  and  free  from  it,  as 
well  as  from  the  calyx,  and  are  said  to  be  hypogynous. 


Endogens.  69 

or  under  the  ovary.  Sometimes  they  are  attached  to 
the  calyx,  but  free  from  the  ovary,  and  are  called 
perigynous,  or  around  the  ovary.  In  other  cases  the 
stamens  appear  above  the  ovary,  and  are  epigynous,  or 
upon  the  ovary.  In  such  instances  the  calyx  is  also 
epigynous.  The  grains  of  pollen  when  discharged 
from  the  anther  are  applied  to  the  stigma,  and  in  a 
short  time  send  forth  tube-like  prolongations  to  the 
ovule  in  the  ovary,  by  which  means  the  embryo  plant 
is  formed.  Many  curious  and  beautiful  arrangements 
are  made  to  ensure  the  proper  application  of  pollen 
to  the  upper  part  of  the  pistil.  In  some  flowers  the 
stamens  have  elastic  filaments  which  are  at  first  bent 
down  and  held  by  the  calyx,  but  when  the  pollen  is 
ripe  the  filaments  jerk  out  and  scatter  the  powder  on 
the  pistil.  The  agency  of  winds  and  of  insects  is 
made  use  of  in  some  cases.  In  the  hazel,  where  the 
pollen  is  in  one  set  of  flowers,  the  leaves  might  inter- 
fere with  the  application  of  pollen,  hence  they  are 
not  produced  until  it  has  been  scattered. 

11.  The  term  fruit  is  applied,  in  botanical  lan- 
guage, to  the  mature  perfect  pistil,  whether  dry  or 
succulent.  Fruits  are  formed  in  different  ways. 
Some,  as  the  pea  and  bean,  consist  solely  of  the 
slightly  altered  pistil ;  others,  as  the  grape,  peach,  and 
plum,  have  the  pistil  so  changed  as  to  be  succulent. 
The  gooseberry,  currant,  apple,  and  pear  are  formed 
by   both   pistil   and  calyx,   a  portion  of  the  latter 


70        Easy  Lessons  in  Vegetable  Biology. 

remaining  at  the  top  of  these  fruits  in  the  form  of 
brownish  scales.  The  hazel-fruit  consists  of  the  pis- 
til developed  into  the  nut,  with  a  covering  of  bracts 
called  the  husk.  The  cup  of  the  acorn  is  also  formed 
by  bracts.  In  the  strawberry,  the  succulent  part  is 
the  enlarged  receptacle,  containing  numerous  small 
carpels,  or  fruits,  often  called  seeds.  The  mulberry, 
pine-apple,  bread-fruit,  pine-cone,  and  fig  are  made 
up  of  numerous  pistils  formed  by  separate  flowers 
and  combined  into  a  common  mass. 

12.  The  seed  is  usually  contained  in  the  seed-vessel 
or  fruit.  If  there  is  no  seed-vessel,  as  in  the  fir,  the 
seed  is  said  to  be  naked.  In  order  that  the  seed  may 
be  complete,  it  must  contain  the  rudiment  of  the 
young  plant,  or  em~bryo. 

"When  the  seed  is  placed  in  favorable  circumstances 
the  little  plant  begins  to  germinate.  Sec.  4.  The 
phenomena  of  sprouting  seed  are  well  seen  in  the 
malting  of  barley.  The  grain  is  exposed  to  moisture, 
heat,  air,  and  is  kept  in  comparative  darkness.  These 
are  favorable  circumstances  analogous  to  prepared 
soil.  A  change  takes  place  in  the  contents  of  the 
grain.  The  starch,  which  is  insoluble  in  water,  and 
unfit  for  the  nourishment  of  the  plant,  is  converted 
into  sugar,  which  is  soluble,  and  easily  absorbed  by 
the  bioplasm  of  the  cells  as  food.  The  young  roots 
are  first  protruded,  and  then  the  stem,  surrounded  by 
a  leaf  called  a  cotyledon,  or  seed-leaf.     If  the  barley 


Endogens. 


71 


were  allowed  to  grow,  the  wliole  of  the  sugar  would 
be  used  by  the  plant.  But  man  wishes  to  get  the 
sugar,  and  lie  therefore  stops  the  growth  of  the  plant 
by  drying  it,  and  thus  makes  malt. 

13.  Grasses  and  Sedges  are  families  of  Endogens 
whose  flowers  have  imbricated  bracts,  or  scales,  called 
glumes,  instead  of  a  colored  perianth.  (Fig.  30.) 

Among  the  grasses  are  classed 
the  nutritious  grains,  as  Wheat, 
Barley,  Oats,  Rye,  Rice,  and 
Indian  Corn. 

14.  The  families  of  Palms 
and  Bananas  are  also  noted 
members  of  the  type  of  En- 
dogens.   (Fig.  31.) 


Linnaeus,  the  father  of  botan- 
ical science,  called  Grasses  the 


Fig.  30. 


plebeians,  and  Palms  the  princes, 
of  the  vegetable  world.  The  latter  are  certainly 
beautiful,  and  often  gigantic,  plants.  As  to  utility  it 
would  be  difficult  to  make  a  comparison.  Various 
species  of  Palms  are  used  for  supplying  food  and  for 
forming  habitations.  The  fruit  of  some  is  edible. 
Many  supply  oil,  wax,  starchy  matter,  and  sugar. 
Their  fibers  make  ropes,  and  various  utensils  are 
formed  from  their  wood  or  fruit. 

15.  The   Orchid  family  has  numerous  species,  re- 
markable for  the  variety  of  forms  and  brilliant  colors 


Fig.  31 


Fig.  32. 


Endogens.  73 

in  their  flowers,  which  often  resemble  insects,  birds, 
and  lizards.  The  visits  of  insects  are  often  needed 
for  their  fertilization. 

16.  The  Lily  family,  including  many  garden  flow- 
ers, as  Tulips,  and  Lilies,  (Fig.  32,)  as  well  as  such 
plants  as  the  Onion,  Squill,  Aloes,  and  Asparagus,  is 
a  beautiful  representative  of  the  type  of  Endogens. 
Other  families,  as  that  of  the  Bulrushes,  have  in- 
complete flowers. 


74        Easy  Lessons  in  Vegetable  Biology. 


CHAPTER  XL 

EXOGENS,  OR  OUTSIDE  GROWERS. 

1.  Plants  which  produce  woody  and  vascular  layers 
near  the  circumference  of  the  stem  are  very  numer- 
ous, including  about  70,000  different  species. 

Between  the  woody  layers,  or  rings,  and  the  bark 
of  such  plants  is  a  semi-fluid  mucilaginous  matter 
containing  the  new  or  growing  cells.  This  layer  is 
called  the  cambium  layer.  At  the  apex  of  the 
stem,  and  at  that  of  the  root,  this  layer  is  continuous 

with  the  cells  of  bioplasm 
which  multiply  by  self-di- 
vision in  these  localities  so 
as  to  supply  the  elements  of 
the  new  tissues.  (Fig.  33.) 
2.  Incomplete  Exog ens  2ccq 
those  whose  flowers  have  no 
corolla.  Sometimes,  but  not 
always,  they  have  a  calyx, 
or  simple  perianth.  They 
are  of  two  kinds :  1)  Those 
whose  seeds  are  naked,  as 
Fig.  33.  in  the  Cone-hearing  family, 

consisting  of  the  Fir  and  Spruce  tribe,  the  Cypress 


EXOGENS. 


tribe,  and  similar  plants.     These  conifers  are  gener- 
ally large   trees   or   evergreen   shrubs,   and  furnish 
much   valuable    timber, 
pitch,    turpentine,     and 
resin.     (Fig.  34.) 

2.  Those  whose  seeds 
are  contained  in  an  ova- 
ry, as  the  Amaranth, 
Buckwheat,  Laurel,  Net- 
tle, Fig,  and  the  Catkin- 
hearing  family.  This 
latter  family  is  the  most 
important  of  this  order, 
since  it  contains  the  most 
important  timber  -  trees, 
as  the  Alder,  Birch,  Wil- 
low, Poplar,  Oak,  Chest- 
nut, etc.  Their  flowers, 
either  male  or  female, 
are  arranged  on  a  com- 
mon axis,  without  sepa- 
rate stalks,  and  are  with- 
out either  calyx  or  corol- 
la, but  furnished  only 
with  scaly  bracts.  Such 
clusters,  or  catkins,  at- 
tract attention  in  early  spring  to  the  willow,  alder,  or 
poplar  trees.     This  family,  with  the  Conifers,  gives 


Fig.  34. 


76 


Easy  Lessons  m  Vegetable  Biology. 


character  to  the  woodland  scenery  of  temperate  climes. 
(Fig.  35.) 

3.  In  the  next  subdivision  of  the  type  of  Exogens 
we  find  plants  whose  flowers  have  both  calyx  and 
corolla.     The  petals  of  the  corolla  are  also  united,  and 


Fig.  35. 

bear  the  stamens,  as  the  Honeysuckle,  Teazel,  Lobelia, 
Convolvulus,  Primrose,  Labiate  and  Composite  fam- 
ilies, etc. 

The  Labiate  family  contains  many  fragrant  and 
aromatic  plants,  as  Mint,  Lavender,  Sage,  Balm,  etc. 
It  is  characterized  by  two  long  and  two  short  stamens, 


Exogens.  77 

four  little  nuts,  or  naked  seeds,  and  irregular  corollas. 
The  Composite  family  is  very  extensive.  It  includes 
all  such  plants  as  the  Thistle,  Sunflower,  Daisy,  Aster, 
and  Chrysanthemum.  There  are  about  twelve  thou- 
sand species  in  this  family,  distributed  all  over  the 
globe.  They  are  generally  herbaceous  plants,  and 
often  contain  a  milky  fluid,  or  latex.  The  flowers  are 
placed  on  a  common  expanded  receptacle,  crowded  to- 
gether into  a  capitulum,  or  head,  and  surrounded  by 
a  general  involucre  of  densely  crowded  bracts.  The 
florets  of  the  central  part  of  the  capitulum  are  often 
of  a  different  structure  and  color  from  those  of  the 
margin,  and  the  two  kinds  are  distinguished  as  florets 
of  the  disk  and  florets  of  the  ray. 

4.  Another  class  of  Exogens  also  have  calyx  and 
corolla,  but  the  corolla  has  distinct  petals,  and  the 
stamens  are  attached  to  the  calyx. 

The  Umbelliferous  family  is  found  in  this  division, 
and  contains  culinary  plants,  such  as  Carrot,  Celery, 
Parsley,  and  Parsnip ;  medicinal  herbs,  as  Caraway, 
Fennel,  Coriander,  and  Assaf cetida ;  and  some  poison- 
ous plants,  as  Hemlock  and  Fool's  Parsley.  This 
family  is  named  from  the  mode  of  its  inflorescence. 
An  umlel,  like  the  capitulum,  has  the  stem  terminat- 
ing in  a  number  of  flowers,  but  each  separate  flower 
is  stalked.  The  umbel  is  simple  when  the  main  stem 
or  peduncle  ends  in  a  number  of  separate  stalked 
flowers,  as  in  the  Cherry,  compound  when  it  branches 


78         Easy  Lessors  in  Vegetable  Biology. 

into  a  number  of  secondary  umbels,  as  in  the  major- 
ity of  genera  in  the  family  of  Umbelliferce. 

The  Zeguminose  family,  characterized  by  the  ovary 
developing  into  a  pod,  (or  legume,)  is  also  very  ex- 
tensive. It  includes  many  forms  of  herbs,  shrubs, 
and  trees.  Some  have  flowers  resembling  a  butterfly, 
and  hence  called  papilionaceous,  as  Clover,  Lupins, 
Peas,  and  Beans.  Others  have  irregular  flowers  which 
are  not  papilionaceous,  as  the  Tamarind-tree  and 
various  species  of  Senna,  or  Cassia.  In  other 
cases  the  flowers  are  regular,  the  scales  of  the  calyx 
in  the  bud  are  vallate,  or  touch  only  at  the  edges, 
and  the  stamens  are  sometimes  very  numerous,  as  in 
different  species  of  Acacia,  and  the  Mimosa,  or  Sen- 
sitive-plant. The  Hose  family  is  also  a  very  large 
one,  and  includes  not  only  the  roses  of  our  gardens? 
but  Raspberries,  Strawberries,  Plums,  Apples,  Pears, 
Cherries,  Peaches,  Apricots,  and  Almonds. 

The  Cactus  family  is  also  found  in  this  division. 
It  contains  many  succulent  plants,  generally  destitute 
of  leaves  whose  place  is  supplied  by  fleshy  stems  of 
grotesque  figures.  Some  are  angular,  others  are 
roundish  and  covered  with  stiff  spines.  They  vary 
in  height  from  a  few  inches  to  twenty  or  thirty  feet. 
The  flowers  are  often  very  showy,  varying  from  pure 
white  to  rich  scarlet  or  purple.  In  Mexico  and 
Southern  California  there  are  numerous  species,  some 
of  gigantic  size.     (Fig.  36.) 


ExOGENS.  Jm 

5.  In  the  highest  class,  or  most  perfect  Exogens, 
the  calyx  and  corolla  are  present,  the  petals  are  disl 


Fig.  36. 

tinct  and  inserted  into  the  receptacle,  and  the  stamens 
grow  from  beneath  the  ovary. 

The  Crowfoot  family,  having  distinct  carpels  above 
numerous  stamens,  and  embracing  the  Hanunculus,  or 
Buttercup,  the  Larkspur,  Aconite,  and  Peony ;  the 
Poppy  family,  having  the  carpels  united  into  an  un- 
divided ovary ;  the  Cruciferous  family,  readily  known 
by  their  four  cruciate  petals,  and  including  many 
flowers  and  vegetables,  as  "Wallflower,  Cabbage,  Tur- 
nip, Eadish,  and  Mustard;  the  Flax  family;  the  Tea 
family,  containing  the  Camellias  and  the  Tea-plants ; 
the  Orange  family;  the  Maple  family;  and  many 
others,  are  found  in  this  group. 


>^?*^vvy 


80        Easy  Lessons  ts  Vegetable  Biology. 


CHAPTER  XII. 

THE  VEGETABLE  CLOTHING  OF  THE  WORLD. 

1.  The  beautiful  forms  of  vegetable  life,  and  the 
peculiarities  of  different  species,  give  character  to  the 
landscape  scenery  of  the  world,  and  the  comparison 
of  the  different  floras  (or  groups  of  plants)  on  the 
earth's  surface  will  aid  us  greatly  in  our  biological 
generalizations. 

2.  The  study  of  the  distribution  of  plants  over  the 
earth  is  sometimes  termed  Botanical  Geography.  It 
has  been  greatly  promoted  by  the  travels  of  Hum- 
boldt. Standing  a  few  hundred  feet  below  the  sum- 
mit of  Chimborazo,  he  saw  an  epitome  of  the  vegeta- 
tion of  the  globe — a  picture  of  all  climates  from  the 
tropics  to  the  poles,  with  their  zones  or  belts  of  vege- 
tation. Just  above  him  rose  the  inaccessible  summit 
of  snow — a  beautiful  image  of  purity  set  in  the  cloud- 
less blue  of  a  tropical  sky.  The  only  vegetation  present 
was  the  Red  Snow,  or  a  few  Thallogens.  The  vol- 
canic rocks  around  him  were  draped  with  Lichens,  a 
few  Mosses,  and  Alpine  flowers.  Beneath,  the  grass- 
green  slopes,  with  varied  flowers  and  willowy  shrubs, 
were  succeeded  by  forest  belts,  and  these  latter  by  the 
tropical  luxuriance  at  the  base  of  the  mountain. 


The  Vegetable  Clothing  of  the  World.     81 

3.  Each  species  of  plant  has  its  center  of  distribu- 
tion at  the  spot  from  which  it  originally  sprang.  It 
is  not  easy,  however,  to  determine  these  centers,  be- 
cause of  plant  migration.  All  plants  are  not 
equally  capable  of  migration,  or  the  strongest  would 
have  replaced  the  rest  and  occupied  all  the  ground. 
Migration  is  also  hindered  by  seas,  deserts,  mountain- 
chains,  and  climate,  as  well  as  by  the  existence  of 
other  plants  and  animals. 

4.  The  transitions  from  one  species  to  another  met 
with  in  gradually  ascending  mountain  regions  are 
not  such  as  Darwin's  theory  of  natural  selection  might 
lead  us  to  expect,  nor  do  they  favor  any  theory  of 
transmutation  of  one  kind  into  another.  Such  a 
mountain-side  is  the  most  appropriate  place  in  the 
world  for  practically  testing  such  theories.  If  any 
transitional  forms  ever  existed  between  species  we 
may  reasonably  expect  to  find  them  here.  But  the 
Alpine  species  make  their  appearance,  and  those  of 
the  plains  disappear  suddenly  at  particular  elevations, 
and  we  find  no  transitional  varieties. 

5.  Climate  has  much  to  do  with  the  similarity  in 
the  floras  of  different  regions.  This  holds  good  in 
widely  separated  regions,  as  seen  in  the  resemblances 
of  the  beeches  of  Japan  and  the  Straits  of  Magellan, 
and  of  the  heaths  of  the  Cape  of  Good  Hope  and  of 
Western  Europe. 

6.  Griesbach  divides  the  surface  of  the  earth  into 

6 


82        Easy  Lessons  in  Vege table  Biology. 

twenty-four  regions  of  vegetation  or  natural  floras. 
Each  of  these  is  subdivided  into  zones,  and  the  char- 
acter of  each  zone  is  determined  by  its  elevation 
above  sea-level.  A  succession  of  zones  is  thus  ob- 
tained until  the  line  of  perpetual  snow  sets  a  limit  to 
vegetable  life.  We  do  not  find  in  nature  such  defi- 
niteness  as  our  classifications  and  theories  imply,  yet 
there  is  a  general  similarity  between  the  flora  of  any 
part  of  the  earth  and  that  of  a  mountain-zone  of  cor- 
responding temperature.  Thus,  similar  and  often 
identical  plants  occur  in  the  lower  zones  of  the  mount- 
ain and  in  the  districts  (north  or  south)  having  an 
increase  of  latitude,  and  this  principle  continues  until 
the  floras  of  the  snow-line  and  of  the  arctic  regions 
generally  correspond.  Yet,  notwithstanding  simi- 
larities, the  floras  of  mountain  and  of  arctic  regions 
show  considerable  differences. 

7.  The  base  of  the  mountains  near  the  equator, 
from  the  sea-level  to  about  2,000  feet  high,  forms  the 
zone  of  palms  and  bananas.  Erom  this  to  the  height 
of  4,500  feet  is  the  zone  of  tree-ferns  and  figs.  In 
India  these  are  covered  by  many  kinds  of  peppers, 
and  orchids.  In  the  islands  of  the  Southern  Ocean 
the  figs  are  replaced  by  tree-like  Urticacece,  and 
the  valuable  cinchona-trees  characterize  the  South 
American  region.  The  zone  of  myrtles  and  laurels 
comes  next,  extending  to  6,000  feet.  The  predomi- 
nant trees  are  those  with  thick,  shining  leaves,  as 


The  Vegetable  Clothing  of  the  Woeld.     83 

myrtles,  camellias,  and  magnolias.  Acacias  and 
heaths  attain  here  their  highest  development,  and 
evergreen  oaks  abound.  The  laurels  occur 
mainly  near  the  upper  limit  of  this  zone,  and  are 
found  also  in  the  next,  the  zone  of  evergreen  trees, 
which  reaches  the  height  of  9,000  feet.  Next  is  the 
zone  of  trees  with  deciduous  foliage,  which  extends 
to  the  height  of  10,000  feet.  In  the  tropics  this  is 
only  seen  on  elevated  plains.  From  this  to  12,500 
feet  is  the  zone  of  conifers,  and  thence  to  15,000  feet 
is  the  zone  of  rhododendrons.  Here  lofty  trees  dis- 
appear, and  are  replaced  by  luxuriant  meadows  and 
herbs  with  thick,  shining  leaves  and  magnificent  flow- 
ers, as  the  rhododendrons  and  azaleas.  The  last  zone 
is  that  of  Alpine  herbs,  extending  to  the  snow-line. 
The  plants  are  chiefly  perennial,  with  woody  roots,  a 
small  amount  of  foliage,  and  brightly  colored  flowers. 
Nearly  all  contain  resinous  and  bitter  substances. 

The  Alps  and  other  mountains  of  temperate  climes 
have  but  five  or  six  zones.  The  zone  of  fruit  trees 
rises  to  about  2,000  feet.  The  apple  and  grape  ascend 
thus  high,  but  the  walnut  may  be  found  up  to  3,000 
feet.  The  woods  here  consist  chiefly  of  beeches, 
alders,  pines,  and  oak.  The  zone  of  beeches  may 
reach  to  5,000  feet.  The  birch,  sycamore,  hazel,  wild 
cherry,  and  many  herbs,  as  the  plantain,  dandelion, 
and  chrysanthemum,  attain  their  upper  limit  here,  and 
disappear  with  the  beech.     At  the  same  time,  we 


84        Easy  Lessons  in  Vegetable  Biology. 

reach  the  lower  limit  of  the  rhododendron,  gentian, 
primrose,  etc.  The  zone  of  pines  comes  next,  to 
6,000  feet.  The  zone  of  Alpine  herbs  extends  to  the 
limit  of  perpetual  snow,  9,000  or  10,000  feet.  The 
dwarf  willow,  a  few  rhododendrons,  the  mountain- 
heath,  and  a  single  azalea  are  all  the  woody  plants 
of  this  zone  in  the  Alps.  The  zone  of  cryptogams, 
or  the  snow  region,  has  only  mosses  and  lichens,  and 
occasionally  the  "  red-snow  plant." 


GLOSSARY  AND   INDEX. 


A'cid  products  of  plants,  31. 

Acotyle'dons,  58 :  plants  without  seed-lobes. 

Ac'rogens,  26,  50 :  plants  which  grow  at  the  summit. 

Albu'men,  12:  in  animals,  white  of  egg  and  similar  material;    in 

vegetables,  the  nourishing  matter  in  seeds,  etc. 
Adventitious,  61:  accidental  or  additional. 
Al'gse,  46 :  water-plants  belonging  to  the  type  of  Thallogens. 
Alkaloids,  31:   active  principles  (not  acids)  of  certain  plants;   as 

morphia,  quinia,  etc. 
Alternate,  64 :  by  turns. 
An'iher,  52:   the  part  of  the  stamen  in  a  flower  which  contains 

pollen. 
Antherid'ia,  51:    the  organ  in    mosses,   etc.,   corresponding  to  the 

anther  in  flowering  plants. 
Antherozo'id,  52  :  the  moving  male  element  in  plants  without  flowers. 
An'nuals,  61 :  yearly  plants. 
An'nular,  35:  ring-like. 
Amce'boid,  18:  resembling  the  Amoeba,  one  of  the  most  primitive 

animals. 
Arachnoidis'cus,  43 :    a  genus  of  Diatoms,  named  for  its  net-like 

markings  on  the  disk. 
Ax/is,  46 :  the  central  column  of  a  plant,  round  which  the  other  parts 

are  arranged. 

Bacteria,  48  :  a  minute  organism,  of  globular  or  rod-like  form,  gener- 
ally regarded  as  one  of  the  Fungi. 
Bast-fibers,  35:  the  vessels  or  fibers  of  inner  bark. 
Bi/oplasm,  13,  15 :  living  germinal  or  formative  matter. 
Bienmial,  61,  pertaining  to  two  years. 
Biol'ogy,  1 :  the  science  of  living  beings. 


86        Easy  Lessons  in  Vegetable  Biology. 

Bipin'nate,  65 :  twice  pinnate,  or  having  two  series  of  leaflets. 

Bot'any,  8:  the  science  of  plants. 

Bracts,  64 :  a  small  leaf,  or  scale,  from  the  axil  of  which  a  flower  or 

its  pedicle  proceeds. 
Bnlbs,  61 :  a  fleshy  roundish  body  consisting  of  scales  or  imperfectly 

developed  leaves,  producing  a  stem  and  roots. 
Buds,  62:  a  small  protuberance  containing  the  rudiments  of  future 

leaves,  flowers,  or  stem. 
Bulrushes,  73:  a  large  kind  of  rush,  growing  in  water. 

Cac'tus,  78:  a  family  of  succulent,  prickly  plants. 

Cap'sule,  9 :  a  sort  of  cup,  or  seed-pod. 

Cam'bium,  38,  59:  the  glutinous  layer  between  the  bark  and  wood, 
from  which  new  tissue  is  made. 

Cam'phor-glands,  36:  groups  of  cells  secreting  camphor. 

Carbon'ic  acid  gas,  31:  a  gas  imbibed  by  plants  for  nutrition,  the 
carbon  being  retained  and  oxygen  given  out. 

Carpels,  70:  the  leaves  forming  the  pistil,  sometimes  separate  and 
sometimes  united  into  a  single  ovary. 

Cat'kins,  75 :  a  mode  of  inflorescence  so  called  from  its  resemblance 
to  a  cat's  tail. 

Capit'ulum,  77  :  a  thick  head  or  cluster  of  flowers,  as  a  clover-top 
or  dandelion. 

Ca/lyx,  68 :  the  outer  leaves  of  a  flower,  generally  green. 

Can'dex,  61 :  the  stem  of  a  palm. 

Cell,  13 :  a  mass  of  living  matter. 

Cell- wall,  27:  the  outer  layer,  or  membrane,  of  vegetable  cells. 

Cel'lulose,  28:  the  starchy  material  of  which  the  cell- wall  is  com- 
posed. 

Cell-contents,  31 :  materials  within  cells. 

Cel/lular-plants,  38 :  a  term  given  to  those  plants  which  are  destitute 
of  vessels. 

Cell-families,  33 :  clusters  proceeding  from  a  single  cell. 

Centers  of  plant  distribution,  80 :  the  original  place  of  plant  growth. 

Cha'ra,  51 :  a  genus  of  Stoneworts. 

Chemical  elements  of  bioplasm,  14. 

Chemical  products  of  bioplasm,  16. 

Chlo'rophyll,  31:  the  green  coloring  matter  in  plants,  which  some- 
times becomes  red,  brown,  etc. 


Glossary  and  Index.  87 

Classification,  23 :  arrangement. 

Class'es,  25 :  primary  modifications  of  types. 

Cil'ia,  41 :  hair-like  projections  from  cells. 

Circulation  in  cells,  28:  movements  of  the  living  matter  within 

Climate,  80 :  its  effects. 

Coales'cence,  52 :  union  of  parts. 

Cork,  34 :  the  healing  tissue  of  plants.    " 

Cor'tex,  37 :  bark. 

Corolla,  6*7 :  the  inner  covering  of  a  flower,  generally  colored,  sur- 
rounding the  stamens  and  pistil. 

Corm,  61  :  a  solid  bulb. 

Cor'date,  65 :  heart-shaped. 

Co'nifers,  75 :  trees  bearing  cones,  like  the  Pines  and  Firs. 

Composite  plants,  77:  having  flowers  gathered  in  a  capitulum  or 
head. 

Cotyle'dons,  58:  seed-lobes. 

Cruciate,  79:  like  a  cross. 

Cru'cifers,  79:  plants  having  cruciform  flowers. 

Crow-foot  family,  79 :  a  family  of  plants,  containing  buttercups,  etc. 

Cu'ticle,  36 :  external  skin. 

Crystals,  31 :  small  chemical  accumulations  found  in  cells. 

Cy'cle,  64:  a  round,  or  set. 

Daugh'ter-cells,  32:  the  progeny  of  a  single  cell. 

Decid'uous,  66 :  falling  off. 

Deposits  on  cell-walls,  29 :  hard  material  left  on  the  external  mem- 
brane, in  shape  of  dots  or  signs. 

Diatoms,  29,  43 :  a  kind  of  unicellular  plants  with  flinty  deposit  on 
the  surlace. 

Dicotyledons,  58:  having  two  seed-lobes. 

Differences  in  bioplasm,  17,  23. 

Diphthe'ria,  48 :  a  diseased  condition  connected  with  the  presence  of 
Fungi. 

Distribution  of  plants,  81. 

Em'bryo,  54,  59:    the  rudimental  or  undeveloped  condition  of  the 

organism. 
En'dogens,  26,  58,  62:  plants  whose  vessels  and  fibers  grow  inside 

the  cellular  tissue  of  the  stem. 


88        Easy  Lessons  in  Vegetable  Biology. 

En'dosmose,  15 :  passage  of  liquid  inward  through  a  membrane  or 

porous  partition. 
Environment,  29  :  surrounding  circumstances. 
Epidermis,  36:  outer  skin. 
Epig'ynous,   69 :  upon  the  ovary,  or  pistil. 
Ex'ogens,  26:    plants  whose  vessels  and  fibers    grow  outside,   or 

between  the  bark  and  wood. 
Ex'osmose,  15  :  passage  of  fluid  outward  through  a  membrane. 
Evolu'tion,  21 :  a  theory  of  development  of  things  from  simple  to 

complex,  by  a  power  within  themselves. 
External  forms  of  plants,  59. 

Family,  25  :  a  group  within  an  order  in  classification. 

Fascic'ulated,  60 :  growing  in  bunches  or  bundles. 

Fermentation,  47 :  a  chemical  change  produced  by  the  growth  of 

a  fungus,  the  yeast- plant. 
Ferns,  52 :  a  class  of  Acrogens,  generally  having  spores  on  the  back 

of  the  fronds  or  leaves. 
Fi'bro-vas'cular,  38,  58:  pertaining  to  vessels  and  fibers. 
Fil'iform,  60:  threadlike. 
Filament,  43,  50,  54:  the  part  of  a  stamen  supporting  the  anther. 

A  thread. 
Flo'rets,  77  :  small  flowers. 

Flo'ra,  80 :  a  group  of  flowers  belonging  to  a  district  or  country. 
Flow'er- structure,  66,  67. 
Forms  of  cells,  30,  31. 
Formed  material.  15 :  material  or  shapes  produced  by  bioplasm,  or 

living  matter. 
Form'ative  layer,  34 :  the  cambium,  or  layer  where  new  cells  grow. 
Frond,  57,  46:  the  leaves  of  Ferns. 
Fun'gi,  46:  a  class  of  Thallogens,  embracing  the  mushrooms  and 

molds. 
Fundamental  tissue,  38  :  the  cellular  parts  of  plants. 
Functions  of  leaves,  65 :  the  uses  served  by  them. 
Fu'siform,  60:  spindle-shaped. 

Geolog'ic  history,  9. 

Ge'nus,  25 :  a  group  within  an  order  in  classification. 

Germ-cell,  54 :  a  cell  answering  to  the  ovary  in  flowering  plants. 


Glossary  and  Index. 


80 


Gen'erating-tissue,  34:  the  cells  which  form  new  tissues. 

Germination  of  seeds,  70. 

Glumes,   71:    husks,  or  scales,  as  in  the  flowers  of  grasses  and 

grain. 
Grass'es,  58,  11 :  a  large  family  of  plants  with  simple  leaves  and 

jointed  stems,  as  wheat,  rye,  oats,  etc. 
Grow'ing-point,  34 :  the  place  of  growth  in  Acrogens. 
Growth  at  summit,  52. 
Growth  of  Ferns,  52. 
Growth  of  Ex'ogens,  74. 
Groups  of  cells,  33. 

Hairs,  31 :  epidermic  appendages. 
Heal'ing-tis'sues,  34. 
Heat,  effects  of,  16. 
Hypog'ynous,  68 :  uuder  the  ovary. 

Identity  of  bioplasm,  22. 

Iner'tia,  11 :  the  tendency  of  matter  to  remain  in  a  state  of  rest  or 
motion. 

Individuals,  25 :  persons  or  things  which  cannot  be  divided  without 
loss  of  identity. 

Incomplete  Ex'ogens,  68,  74:  those  whose  flowers  have  no  co- 
rolla. 

Indu'sium,  54:  a  membranous  covering  to  the  fruit-spot  of  some 
Ferns. 

Inherent  mo'tion,  18:  movement  originating  from  within. 

In'stinct,  45 :  an  inward  impulse,  or  tendency. 

In'ternodes,  51:  the  space  between  the  nodes,  or  places  whence  the 
leaves  arise. 

Inflorescence,  11:  mode  of  flowering. 

Involu'cre,  11 :  a  whorl  or  set  of  bracts  around  a  flower,  umbel,  or 
head. 

La'biate,  76:  plants  whose  flowers  have  leaf-like  projections 

Landscape  scen'ery,  81. 

La'tex,  35:  fluid,'  generally  milky,  contained  in  special  vessels    and 

holding  peculiar  substances  in  solution. 
Lan'ceolate,  65 :  oblong  and  tapering. 


90         Easy  Lessons  in  Vegetable  Biology. 

Legu'minose,  18 :  plants  having  legumes,  or  pods. 

Leaves,  63. 

Lich'ens,  46:  a  class  of  Thallogens,  often  improperly  called  rock- 
moss,  or  tree-moss. 

Life,  9 :  the  power  by  which  organized  beings  live,  or  the  state  of 
animate  existence. 

Life  his'tories,  8. 

Living  matter,  1 2 :  bioplasm. 

LiHes,  73:  a  large  family  of  flowering  plants,  including  lilies,  tu- 
lips, etc. 

Materialism,  10:  the  dogma  that  all  things  consist  of  matter  alone. 
Med'ullary  rays,  39 :  rays  of  cellular  tissue  or  pith,  passing  from  the 

center  to  the  bark. 
Metamor'phosis,  53 :  transformation,  or  change  of  form  or  shape. 
Microscopic  sections,  39. 
Mo'tions  of  bioplasm,  18. 
Mo'tile,  45 :  having  power  of  self-motion. 
Monocotyle'dons,  58:  plants  with  single  seed-lobe. 
Moth'er-cells,  32 :  the  cell  from  which  others  originate. 
Moss'es,  54:    a  class  of  Acrogens,  with  plants  of  small  size,  and 

stems  with  narrow,  simple  leaves. 
Mountain- vegetation,  83. 
Molds,  47  :  minute  fungous  plants. 
Multiplication  of  cells,  32. 
Myce'lium,  48  :  the  filaments,  or  spawn,  from  which  a  fungus  grows. 

Names  of  species,  25. 
Na'ked,  68 :  without  calyx  or  corolla. 
Na'piform,  60  :  turnip  shaped. 
Neb'ulous,  8 :  cloudy  or  misty. 

Neb'ular  hypothesis,  8 :  theory  of  development  of  worlds  from  primi- 
tive fire-mist. 
Nec'taries,  36 :  groups  of  cells  which  secrete  honey. 
Nu'cleus.  28:  a  concentration  of  vital  power  in  a  cell. 
Nucleolus,  28:  a  secondary  nucleus. 

Nodes,  51 :  points  on  the  stem  from  which  the  leaves  proceed. 
Nutrition,  20 :  the  process  of  nourishment; 


Glossary  and  Index.  91 

O'ospore,  52:  the  embryo  of  Acrogens,  etc. 

Or'chids,  11:  a  group  of  plants  with  very  peculiar  flowers. 

Or'ders,  25 :  subdivisions  of  classes. 

Organ/ic  forms,  45  :  forms  of  animals  or  vegetables. 

Organiza'tion,  9,  27  :  the  arrangement  of  organs  or  parts. 

Or'gans  of  nutrition,  66. 

Oil-pas'sages,  36 :  cavities  conveying  oil. 

O'vary,  68 :  the  lower  part  of  the  pistil. 

O'vate,  65 :  egg-shaped. 

O'vule,  68  :  a  young  seed. 

Pab'ulum,  15 :  food. 

Palms,  71 :  a  group  of  conspicuous  tropical  plants. 

Pedun'cle,  77  :  the  stalk  of  the  flower  or  fruit. 

Perianth,  68 :  the  envelope  of  the  flower  when  caylx  and  corolla  are 
indistinguishable. 

Perig'ynous,  69  :  around  the  ovary. 

Permanent  tis'sue,  34 :  bells  in  a  plant  incapable  of  further  growth. 

Peren'nial,  61:  plants  which  live  more  than  two  years. 

Petiole,  64  :  the  foot-stalk  of  a  leaf. 

Pet'al,  68  :  the  leaf  of  the  corolla. 

Pin'nate,  65 :  a  compound  leaf,  with  leaflets  along  a  common  pe- 
tiole. 

Pis'til,  67  :  the  central  organ  of  a  flower. 

Papiliona'ceous,  78:  butterfly -like. 

Pin'nule,  54 :  a  branchlet  of  a  pinnate  frond  or  leaf. 

Pol'len,  69 :  the  fecundating  dust  in  the  anther  of  a  flower. 

Pop'pies,  79  :  a  genus  of  flowering  plants. 

Physical  forces  in  bioplasm,  15. 

Pith,  39 :  the  central  cells  in  the  stem  of  plants. 

Primordial  u'tricle,  28 :  the  mucilaginous  layer  within  the  cell-wall 
of  a  cell. 

Pro'tococcus,  40  :  a  genus  of  primitive  plants. 

Pro'tophytes,  26  :  the  simplest  type  of  plants. 

Plant  migration,  81. 

Pro-em'bryo,  52  :  a  temporary  structure  in  the  early  life-history  of 
Acrogens.  etc. 

Pro'toplasm,  13:  the  physical  basis  of  life,  or  rather,  of  living 
matter. 


92        Easy  Lessons  in  Vegetable  Biology. 

Prothallium,  54:  a  structure  in  Ferns  similar  to  the  pro-embryo  in 

Stone-worts. 
Putrefaction,  47 :  decay  of  albuminoid  matter,  produced  by  the  action 

of  Fungi. 
Radical,  65  :  belonging  to  the  root. 
Receptacle,  68 :  the  tip  of  the  flower-stalk,  sometimes  dilated,  which 

supports  the  organs  or  florets. 
Retic'ulated,  35  :  like  a  net- work. 
Red  snow,  42  :  one  of  the  type  of  Protophytes. 
Re'gions  of  vegeta'tion,  82. 

Reproduction,  20 :  the  multiplication  of  cells  or  individuals. 
Resem'blances  of  bi/oplasm,  14. 
Rhizome',  53 :  an  under-ground  stem. 
Roots,  59. 

Ros'es,  78 :  a  family  of  flowering  plants. 
Run'ners,  61 :  branches  of  stems  which  give  off  roots  from  their 

nodes. 
Rust  in  wheat,  48:  a  species  of  fungus. 

Sea-weeds,  46. 

Scales,  62 :  undeveloped  leaves  protecting  buds,  etc. 

Scape,  61 :  a  flower-stem  without  leaves. 

Sagittate,  65 :  arrow-shaped. 

Seeds,  70:  the  part  containing  the  embryo  in  flowering  plauts. 

Sedg/es,  71 :  a  family  of  plants  similar  to  rushes. 

Se'pals,  68 :  the  leaves  of  the  calyx. 

Sieve-tubes,  35 :  cells  forming  tubes  by  sieve-like  perforations  through 

adjacent  ends. 
Ses'sile,  64,  68 :  without  footstalk. 
Scalarfform,  53:  ladder-like. 
Show'ers  of  blood,  42. 
Shapes  of  leaves,  65. 
Soul  and  life,  10. 

Sorus,  54 :  the  fruit-spot  on  a  fern. 

Spores,  52:  parts  analogous  to  the  seeds  of  flowering  plants. 
Spore'-cases,  52 :  the  vessels  containing  the  spores  in  Ferns,  etc. 
Sporan'gia,  51 :  spore-cases. 
Spe'cies,  25  :  a  group  of  individuals  which  may  have  descended  from 

a  single  pair. 


Glossary  and  Index.  93 

Spontaneous  genera/tiou,  21. 

Spi'ral  arrangement  of  leaves,  64. 

Sta'mens,  67 :  the  male  organs  in  flowers. 

Stems,  60 :  the  stalk,  or  part  which  bears  the  leaves,  flowers,  and 
fruit. 

Starch,  31. 

Stig'ma,  68  :  the  upper  part  of  the  pistil. 

Stip'ule,  64 :  leaf-like  appeudages  to  the  petiole. 

Sto'ma,  36:  the  opening  between  the  cells  of  epidermis  for  evapora- 
tion, etc. 

Stone' worts,  50 :  an  order  of  Acrogens. 

Squamose,  61 :  scaly  as  the  cone  of  a  pine. 

Style,  68 :  the  pillar  or  filament,  supporting  the  stigma  of  the  pistiL 

Suc'culent,  69  :  juicy,  fleshy. 

Tei/nate,  65 :  an  arrangement  of  three  leaflets  on  a  petiole. 

Thallogens,  26:  a  type  of  plants. 

The'oriesoflife,  10. 

Transitional  forms  unknown,  80. 

Tu'ber,  61 :  a  fleshy  rounded  stem  or  root,  as  the  potato. 

Tu'berous,  60 :  containing  tubers. 

Tu'nicated,  61 :  covered  with  layers,  as  the  onion. 

Tripin'nate,  65  :  bipinnate  leaves  on  each  side  of  a  petiole. 

Types,  25,  26:  general  plans  of  structure. 

Unicellular,  40  :  having  a  single  cell. 

Un'ion  of  cells,  33. 

Unorganized,  27  :  matter  which  has  not  lived. 

Um'bel,  77 :  a  flower  cluster  in  which  the  stalks  spread  from  a  com- 

mon  point. 
Umbelliferous,  77:  bearing  umbels. 

Varieties,  25 :  races  or  breeds  among  species. 
Yas'cular,  38 :  belonging  to  vessels. 
Yalv'ate,  78 :  meeting  at  the  edges  without  overlapping. 
Vessels,  35 :  tubes  or  canals  among  the  cells. 

Wa'ter  in  bioplasm,  14. 
White  blood-cells,  13,  20. 


94        Easy  Lessons  m  Vegetable  Biology. 

Whorls,  50 :  an  arrangement  of  leaves,  or  organs,  around  the  stem  in 
the  same  plane. 

Yeast-plant,  47  :  a  fungus  which  is  the  cause  of  fermentation. 

Zool/ogy,  7  :  science  of  animal  life. 

Zoospores,  41 :  spores  having  spontaneous  movements. 

Zones  of  vegetation,  83. 

r^  Of  TEM^ 

[uiivmsiti 

THE   END. 


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